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Pembuatan toksoid

Pembuatan toksoid


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Toksoid yang dihasilkan oleh bakteria tetanus dan difteria dinyahtoksik dengan formaldehid, namun sifat antigennya kekal.

Sumber : Sains Biologi oleh Taylor

Apakah yang dilakukan oleh formaldehid?


Toksin kedua-duanya Clostridium tetani dan Corynebacterium diphtheriae sangat toksik sehingga anda tidak boleh menggunakannya untuk imunisasi, kerana jumlah yang diperlukan untuk penghasilan antibodi yang betul akan membunuh individu tersebut. Untuk tujuan itu toksin "nyah toksin" dengan bertindak balas dengan formaldehid yang menghilangkan ketoksikan tetapi toksoid yang terhasil masih imunogenik. Ini berlaku melalui tindak balas formaledehid dengan kumpulan amino bebas rantai sampingan asid amino untuk membentuk kumpulan azometin. Ini mengubah protein dengan begitu banyak, sehingga ia tidak boleh mengikat glangliosides lagi yang menjadikannya tidak toksik. Sistem imun masih boleh mengenali bahagian yang tidak diubah suai (untuk ini 8-10 asid amino dalam satu regangan sudah mencukupi) dan membuat antibodi.


Kod Sistem Klasifikasi Perindustrian Amerika Utara (NAICS) Digunakan untuk Mencipta Senarai Organisasi Yang Amat Terpengaruh

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Pembuatan Persediaan Farmaseutikal

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Pembuatan Bahan Diagnostik In-Vitro

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan bahan diagnostik in-vitro (iaitu, tidak diambil secara dalaman), seperti bahan kimia, biologi atau radioaktif. Bahan tersebut digunakan untuk ujian diagnostik yang dilakukan dalam tabung uji, piring petri, mesin dan peranti jenis ujian diagnostik yang lain.

Pembuatan Produk Biologi (kecuali Diagnostik).

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan vaksin, toksoid, pecahan darah dan media kultur yang berasal dari tumbuhan atau haiwan (kecuali diagnostik).

Semua Pembuatan Jentera Perindustrian Lain

Industri AS ini terdiri daripada pertubuhan yang terutamanya terlibat dalam pembuatan jentera perindustrian (kecuali pertanian dan jenis ladang, pembinaan dan perlombongan, kilang papan dan kerja kayu, pembuatan plastik dan getah, pembuatan kertas dan papan kertas, tekstil, mesin dan peralatan percetakan, mesin jenis pembuatan makanan, dan mesin pembuatan semikonduktor).

Pembuatan Alat Optik dan Kanta

Industri AS ini terdiri daripada pertubuhan yang terlibat terutamanya dalam satu atau lebih daripada yang berikut: (1) pembuatan instrumen dan kanta optik, seperti teropong, mikroskop (kecuali elektron, proton), teleskop, prisma dan kanta (kecuali oftalmik) (2) salutan atau kanta penggilap (kecuali oftalmik) dan (3) kanta pelekap (kecuali oftalmik).

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Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan relau proses industri, ketuhar, peralatan pemanasan aruhan dan dielektrik serta tanur (kecuali simen, kimia, kayu).

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam skala dan neraca pembuatan (kecuali makmal).

Industri AS ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan mesin tujuan am (kecuali pengudaraan, pemanasan, penyaman udara, dan peralatan penyejukan komersil mesin kerja logam enjin, turbin, dan peralatan penghantaran kuasa pam & pemampat peralatan pengendalian bahan peralatan tangan didorong kuasa kimpalan & pematerian jentera pembungkusan peralatan relau proses industri & ketuhar silinder kuasa bendalir & amp penggerak pam kuasa bendalir & motor dan penimbang & neraca).

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Pembuatan Radas Elektroperubatan dan Elektroterapeutik (Peranti Pengimejan)

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan radas elektroperubatan dan elektroterapeutik, seperti peralatan pengimejan resonans magnetik, peralatan ultrasound perubatan, perentak jantung, alat bantu pendengaran, elektrokardiograf dan peralatan endoskopi elektroperubatan.

Instrumen dan Produk Berkaitan

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam instrumen pembuatan dan peranti berkaitan untuk mengukur, memaparkan, menunjukkan, merekod, menghantar dan mengawal pembolehubah proses industri. Instrumen ini mengukur, memaparkan atau mengawal (monitor, menganalisis, dan sebagainya) pembolehubah proses industri, seperti suhu, kelembapan, tekanan, vakum, pembakaran, aliran, aras, kelikatan, ketumpatan, keasidan, kepekatan dan putaran.

Pembuatan Radas Penyinaran

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan radas penyinaran dan tiub untuk aplikasi, seperti diagnostik perubatan, terapeutik perubatan, perindustrian, penyelidikan dan penilaian saintifik. Penyinaran boleh berbentuk sinar beta, sinar gamma, sinar-X atau sinaran mengion yang lain.

Pembuatan Alat Pembedahan dan Perubatan

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan peralatan dan radas perubatan, pembedahan, oftalmik dan veterinar (kecuali radas elektroterapeutik, elektroperubatan dan penyinaran). Contoh produk yang dibuat oleh pertubuhan ini ialah picagari, jarum hipodermik, alat anestesia, peralatan pemindahan darah, kateter, pengapit pembedahan dan termometer perubatan.

Pembuatan Perkakas dan Bekalan Pembedahan

Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan peralatan dan bekalan pembedahan. Contoh produk yang dibuat oleh pertubuhan ini ialah peranti ortopedik, peralatan prostetik, pembalut pembedahan, tongkat, jahitan pembedahan dan peranti keselamatan industri peribadi (kecuali cermin mata pelindung).

Pembuatan Peralatan dan Bekalan Pergigian

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Pembuatan Baik Oftalmik

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Industri A.S. ini terdiri daripada pertubuhan yang terlibat terutamanya dalam pembuatan gigi palsu, mahkota, jambatan dan peralatan ortodontik yang disesuaikan untuk kegunaan individu

Penyelidikan & Pembangunan dalam Bioteknologi

Penyelidikan dan Pembangunan dalam Sains Sosial dan Kemanusiaan

Industri ini terdiri daripada pertubuhan yang terlibat terutamanya dalam menjalankan penyelidikan dan analisis dalam pembangunan kognitif, sosiologi, psikologi, bahasa, tingkah laku, ekonomi, dan penyelidikan sains sosial dan kemanusiaan yang lain.

Sila hubungi Timbalan Kaunselor Etika IC anda( ,1 muka surat) atau Penyelaras Etika( ,4 muka surat) untuk mendapatkan bantuan.


Vaksin Hidup, Dilemahkan

Vaksin yang dilemahkan boleh dibuat dalam beberapa cara yang berbeza. Beberapa kaedah yang paling biasa melibatkan penyebaran virus penyebab penyakit melalui satu siri kultur sel atau embrio haiwan (biasanya embrio anak ayam). Menggunakan embrio anak ayam sebagai contoh, virus itu ditanam dalam embrio yang berbeza dalam satu siri. Dengan setiap laluan, virus menjadi lebih baik dalam mereplikasi dalam sel anak ayam, tetapi kehilangan keupayaannya untuk mereplikasi dalam sel manusia. Virus yang disasarkan untuk digunakan dalam vaksin boleh ditumbuhkan melalui—"dilalui" melalui—lebih daripada 200 embrio atau kultur sel yang berbeza. Akhirnya, virus yang dilemahkan tidak akan dapat mereplikasi dengan baik (atau sama sekali) dalam sel manusia, dan boleh digunakan dalam vaksin. Semua kaedah yang melibatkan penyebaran virus melalui perumah bukan manusia menghasilkan versi virus yang masih boleh dikenali oleh sistem imun manusia, tetapi tidak dapat mereplikasi dengan baik dalam perumah manusia.

Apabila virus vaksin yang terhasil diberikan kepada manusia, ia tidak akan dapat mereplikasi cukup untuk menyebabkan penyakit, tetapi masih akan mencetuskan tindak balas imun yang boleh melindungi daripada jangkitan masa depan.

Satu kebimbangan yang mesti dipertimbangkan ialah potensi virus vaksin untuk kembali kepada bentuk yang boleh menyebabkan penyakit. Mutasi yang boleh berlaku apabila virus vaksin mereplikasi dalam badan boleh mengakibatkan ketegangan yang lebih ganas. Ini sangat tidak mungkin, kerana keupayaan virus vaksin untuk mereplikasi sama sekali adalah terhad, namun ia diambil kira semasa membangunkan vaksin yang dilemahkan. Perlu diingat bahawa mutasi adalah agak biasa dengan vaksin polio oral (OPV), vaksin hidup yang ditelan dan bukannya disuntik. Virus vaksin boleh bermutasi menjadi bentuk ganas dan mengakibatkan kes polio lumpuh yang jarang berlaku. Atas sebab ini, OPV tidak lagi digunakan di Amerika Syarikat, dan telah digantikan pada Jadual Imunisasi Kanak-kanak yang Disyorkan oleh vaksin polio tidak aktif (IPV).

Perlindungan daripada vaksin hidup yang dilemahkan biasanya bertahan lebih lama daripada yang diberikan oleh vaksin yang dibunuh atau tidak diaktifkan.


Pembuatan Vaksin

Pembuatan vaksin telah popular secara meluas sejak Pasteur membangunkan vaksin rabies pada tahun 1885. Sejak itu pembuatan vaksin terus popular kerana pertahanan yang diberikan oleh vaksin terhadap virus tertentu. Sistem imun manusia sentiasa mempertahankan dirinya daripada serangan virus dan kita hanya kekurangan keupayaan untuk mengenali dan melawan patogen yang sentiasa berubah ini. Vaksin direka bentuk untuk membantu menggerakkan sistem imun perumah untuk mencegah jangkitan virus dan memutuskan rantaian penularan.

Pembangunan dan pembuatan vaksin telah membawa kepada vaksin terhadap Hepatitis A dan B, influenza, campak, beguk dan polio hanya untuk menamakan beberapa sahaja. Imunisasi telah membantu banyak penyakit kanak-kanak yang menyebabkan sejumlah besar kematian mengikut sejarah, menjadi sangat jarang berlaku dengan hanya beberapa atau tiada kes setahun.

Taktik untuk pembuatan vaksin bergantung pada dua jenis vaksin utama:

  • Kekebalan aktif: Dicetuskan selepas menyuntik versi diubah suai atau sebahagian daripada patogen ke dalam penerima dengan merangsang tindak balas imun terhadap agen berjangkit. Ini memberikan perlindungan jangka panjang daripada virus berkenaan.
  • Kekebalan pasif: Terinduksi selepas menyuntik antibodi atau agen sekunder yang ditujukan terhadap patogen ke dalam penerima. Walaupun ini adalah perlindungan jangka pendek daripada patogen, bergantung kepada virus ini mungkin sahaja yang diperlukan.

Pembuatan vaksin bergantung pada pemprosesan virus ibu bapa yang ganas dalam empat cara berbeza:

Pembuatan vaksin yang menggunakan virus yang dilemahkan (hidup) merangsang tindak balas imun akibat replikasi virus. Jangkitan ini menyebabkan penyakit ringan atau tidak jelas berbanding dengan virus liar. Contoh vaksin yang dibuat melalui pengecilan patogen ialah vaksin influenza yang ditadbir secara intranasal. Virus ini hanya mereplikasi dalam nasofaring yang menghasilkan imuniti pelindung kepada virus influenza.

Pembuatan vaksin bagi vaksin yang tidak aktif memerlukan rawatan kimia menggunakan agen seperti detergen formalin atau bukan ionik. Pembuatan vaksin jenis ini menghapuskan kejangkitan sambil tidak menjejaskan antigenisiti. Contoh vaksin yang dihasilkan menggunakan pembuatan vaksin jenis ini ialah vaksin poliovirus yang dicipta pada tahun 1954.

Pembuatan vaksin menggunakan fraksinasi telah digunakan secara meluas semasa membuat vaksin influenza dan demam kuning. Teknik pembuatan vaksin jenis ini terdiri daripada pemisahan zarah virus dalam subunitnya, secara de facto menyahaktifkan virus patogen. Dos pecahan telah dinaikkan kepentingannya kerana kawalannya terhadap wabak apabila bekalan vaksin adalah terhad.

Pembuatan vaksin rekombinan membolehkan untuk mengklon dan mengeluarkan komponen virus tunggal dan melakukan imunisasi terhadap komponen tunggal yang disucikan. Gen virus klon (cth. Protein Capside) boleh diekspresikan dalam bakteria, yis, serangga atau sel mamalia dan kemudiannya disucikan untuk perumusan akhir. Pembuatan vaksin jenis ini digunakan untuk menghasilkan vaksin hepatitis B.

Proses Pengilangan Vaksin &ndash gambaran keseluruhan

Pembuatan vaksin terdiri daripada beberapa peringkat (1). Pada langkah pertama, antigen yang mendorong tindak balas imun dihasilkan. Memandangkan antigen virus biasanya dibentangkan oleh virus asli, pembuatan vaksin secara historis bergantung pada pertumbuhan virus dalam sel primer yang dikultur, garisan sel berterusan atau telur ayam (bergantung pada tropisme) untuk penghasilan zarah virus keseluruhan. Selain itu, pertumbuhan virus khusus bakteria dalam bakteria yang ditanam dalam bioreaktor boleh digunakan untuk pembuatan bakteriofaj untuk Paparan Phage (6) dan lebih baru untuk pembangunan vaksin bakteria (7).

Pada masa kini pembangunan lanjut teknologi pengeluaran protein rekombinan membolehkan ekspresi peptida antigen terpencil dalam organisma seperti bakteria, yis dan garisan sel mamalia, meningkatkan konsistensi proses huluan dan hiliran.

Dalam langkah kedua, zarah virus dikumpulkan dan diproses selanjutnya. Virus yang tidak dilemahkan mungkin perlu dinyahaktifkan melalui kaedah kimia atau fizikal, tetapi secara amnya tiada penulenan lanjut diperlukan. Protein rekombinan sebaliknya memerlukan langkah penulenan lanjut (hiliran) termasuk ultrafiltrasi dan kromatografi lajur.

Pada langkah terakhirnya, vaksin diformulasikan dengan menambah adjuvant, penstabil, dan pengawet mengikut keperluan. Adjuvant meningkatkan tindak balas imun terhadap antigen, penstabil meningkatkan hayat penyimpanan, dan pengawet membenarkan penggunaan vial multidose.

Pembuatan vaksin sedang berkembang. Sel mamalia yang dikultur dijangka menjadi semakin penting berbanding pilihan konvensional yang menggunakan telur ayam (5). Pembuatan vaksin bergantung pada sel mamalia kerana produktiviti yang lebih tinggi dan insiden rendah masalah pencemaran berbanding pembuatan vaksin menggunakan telur (1). Teknologi rekombinan yang menghasilkan vaksin detoks secara genetik dijangka semakin popular untuk penghasilan vaksin bakteria yang menggunakan toksoid (1). Vaksin gabungan dijangka dapat mengurangkan kuantiti antigen yang terkandung di dalamnya, dan dengan itu mengurangkan interaksi yang tidak diingini, dengan menggunakan corak molekul yang berkaitan dengan patogen.

Terdapat banyak tekanan kos apabila mengeluarkan vaksin. Menghasilkan vaksin dalam telur telah menjadi amalan sejarah dengan pembuatan vaksin menggunakan talian sel menjadi usaha yang lebih baru. Mempunyai nombor sel kritikal, menghasilkan sebanyak mungkin vaksin, dan mengurangkan pembolehubah atau aktiviti hiliran yang membosankan adalah satu kemestian untuk pembuatan vaksin.

Walaupun sesetengah pengeluar telah berjaya menghasilkan vaksin selama beberapa dekad, yang lain telah goyah atau gagal, dan maklumat yang agak sedikit tersedia dalam literatur tentang cabaran, kerumitan dan kos pembuatan vaksin (1).

Hasil boleh berbeza-beza secara meluas disebabkan oleh gabungan kebolehubahan biologi yang hampir tidak terhingga dalam bahan permulaan asas, mikroorganisma itu sendiri, keadaan persekitaran kultur mikrob, pengetahuan dan pengalaman juruteknik pembuatan, dan langkah-langkah yang terlibat dalam proses penulenan (1) .

Pihak berkuasa pengawalseliaan melesenkan bukan sahaja entiti biologi tertentu, tetapi juga proses yang mana entiti itu dihasilkan, diuji dan dikeluarkan untuk digunakan. Perubahan halus dalam proses pengeluaran boleh mengubah produk akhir dan mengubah ketulenan, keselamatan atau keberkesanannya.

Banyak paten vaksin melindungi proses pembuatan dan bukannya antigen yang dihasilkan oleh proses tersebut. Penekanan pada pembangunan proses adalah faktor kejayaan utama untuk menjadi yang pertama memasarkan dengan biofarmaseutikal baharu dan pembangunan proses yang tidak mencukupi sering dikaitkan dengan kegagalan pembangunan produk peringkat akhir. Sesiapa yang ingin membangunkan vaksin baharu mesti mengingati pengeluaran komersial untuk membantu menghentikan kegagalan pembangunan produk peringkat akhir. Penekanan pada pembangunan proses adalah faktor utama untuk mempercepatkan masa ke pasaran. Media bebas serum membantu mengurangkan pembolehubah dan menyediakan produk berprestasi yang konsisten untuk pembuatan vaksin. Beralih daripada penggunaan serum meningkatkan kebolehulangan dan titer virus. Menggunakan medium bebas serum yang juga bebas protein memudahkan pemprosesan hiliran yang mengurangkan beban kerja dan kos yang meningkatkan kebimbangan dalam pembuatan vaksin. Menyingkirkan kos serum yang tinggi, masa pemprosesan yang besar untuk kultur berasaskan telur, dan menyediakan produk mesra kawal selia agar mudah dimasukkan ke dalam mana-mana aliran kerja pembuatan vaksin adalah semua faedah menggunakan media bebas serum untuk pengeluaran vaksin.

Lonza telah membangunkan pelbagai media yang boleh digunakan untuk pembuatan vaksin. Sama ada menggunakan sel serangga, sel MDCK, sel Vero atau sel HEK293, Lonza mempunyai banyak pilihan media bebas serum yang akan membolehkan pembuatan vaksin yang berjaya yang membantu dalam mengurangkan kos, mengurangkan pembolehubah dan menyediakan produk mesra kawal selia untuk banyak proses pembuatan vaksin. Jika serum kekal sebagai bahagian penting dalam aliran kerja pembuatan vaksin anda, portfolio media klasik Lonza&rsquos telah digunakan secara meluas dalam pelbagai aplikasi. Jika protein virus rekombinan adalah produk yang dikehendaki untuk aliran kerja pembuatan vaksin anda, Lonza menggunakan pelbagai produk untuk penghasilan protein.


Ketekalan, Keselamatan, Toleransi dan Imunogenisiti Vaksin Heksavalen Penyiasatan pada Bayi AS

latar belakang: Kajian fasa III berbilang pusat ini (NCT01340937) menilai konsistensi tindak balas imun terhadap 3 lot berasingan toksoid difteria-tetanus-aselular pertusis 5, vaksin poliovirus tidak aktif, Haemophilus influenzae jenis b, dan hepatitis B (DTaP5-IPV-Hib-HepB), vaksin heksavalen penyiasatan (HV).

Kaedah: Bayi yang sihat secara rawak (2:2:2:1) untuk menerima HV atau Pentacel (Kawalan). Kumpulan 1, 2 dan 3 menerima HV pada 2, 4 dan 6 bulan, dan Kawalan pada 15 bulan. Kumpulan 4 menerima Kawalan pada 2, 4, 6 dan 15 bulan, ditambah dengan Recombivax HB (HepB) pada 2 dan 6 bulan. Prevnar 13 serentak diberikan kepada semua kumpulan pada 2, 4, 6 dan 15 bulan vaksin pentavalent rotavirus (RV5) diberikan kepada semua kumpulan pada 2, 4 dan 6 bulan. Spesimen darah (3-5 mL) dikumpulkan sejurus sebelum pemberian dos 1, selepas dos 3, sejurus sebelum dos kanak-kanak, dan selepas dos kanak-kanak. Kejadian buruk direkodkan selepas setiap vaksinasi.

Keputusan: 3 lot pembuatan HV menyebabkan tindak balas antibodi yang konsisten terhadap semua antigen. Imunogenisiti HV adalah tidak lebih rendah daripada Kawalan untuk semua antibodi, kecuali bagi pertusis filamen hemagglutinin geometrik min kepekatan postdose 3, dan pertussis pertactin (PRN) kepekatan purata geometri selepas dos kanak-kanak. Keimunogenan selepas dos 3 bagi Prevnar 13 yang ditadbir serentak secara amnya adalah serupa (kecuali serotype 6B) apabila diberikan dengan HV atau Kawalan. Kejadian buruk HV adalah serupa dengan Kawalan, kecuali untuk kadar demam yang lebih tinggi ≥38.0°C [49.2% vs. 35.4%, anggaran perbezaan 13.7% (8.4, 18.8)].

Kesimpulan: HV menunjukkan keselamatan konsisten pembuatan lot-to-lot dan imunogenisitas adalah setanding dengan vaksin berlesen. HV menyediakan pilihan vaksin gabungan baharu dalam siri vaksin 2 bulan, 4 bulan dan 6 bulan AS.


Kandungan

Vaksin pertusis aselular (aP) dengan tiga atau lebih antigen menghalang kira-kira 85% daripada kes batuk kokol biasa pada kanak-kanak. [3] Ia mempunyai keberkesanan yang lebih tinggi atau serupa dengan vaksin pertusis sel keseluruhan yang digunakan sebelum ini, namun keberkesanan vaksin aselular merosot lebih cepat. [3] Vaksin aselular juga menyebabkan lebih sedikit kesan sampingan berbanding vaksin sel keseluruhan. [3]

Walaupun vaksinasi meluas, pertusis telah berterusan dalam populasi yang divaksin dan merupakan salah satu penyakit yang boleh dicegah dengan vaksin yang paling biasa. [8] Kebangkitan baru-baru ini dalam jangkitan pertusis dikaitkan dengan gabungan penurunan imuniti dan mutasi baru dalam patogen yang tidak dapat dikawal oleh vaksin sedia ada dengan berkesan. [8] [9]

Sesetengah kajian telah mencadangkan bahawa walaupun vaksin pertusis aselular berkesan untuk mencegah penyakit ini, ia mempunyai kesan terhad pada jangkitan dan penularan, bermakna orang yang diberi vaksin boleh menyebarkan penyakit itu walaupun mereka mungkin hanya mempunyai simptom ringan atau tiada langsung. [10] [11]

Kanak-kanak Edit

Bagi kanak-kanak, imunisasi biasanya diberikan dalam kombinasi dengan imunisasi terhadap tetanus, difteria, polio, dan haemophilus influenzae jenis B pada usia dua, empat, enam, dan 15-18 bulan. [12]

Dewasa Edit

Pada tahun 2006 CDC mengesyorkan orang dewasa menerima vaksinasi pertusis bersama-sama dengan penggalak toksoid tetanus dan difteria. [13] Pada tahun 2011 mereka mula disyorkan penggalak semasa setiap kehamilan. [13] Di UK, vaksinasi wanita hamil (antara 28 dan 38 minggu kehamilan) juga disyorkan. [14]

Penggalak pertusis untuk orang dewasa digabungkan dengan vaksin tetanus dan penggalak vaksin difteria gabungan ini disingkatkan "Tdap" (Tetanus, difteria, pertusis acellular). Ia serupa dengan vaksin zaman kanak-kanak yang dipanggil "DTaP" (Difteria, Tetanus, Pertusis aselular), dengan perbezaan utama bahawa versi dewasa mengandungi jumlah komponen difteria dan pertusis yang lebih kecil—ini ditunjukkan dalam nama dengan penggunaan lebih rendah- kes "d" dan "p" untuk vaksin dewasa. Huruf kecil "a" dalam setiap vaksin menunjukkan bahawa komponen pertusis adalah aselular, atau bebas sel, yang mengurangkan kejadian kesan sampingan. Komponen pertusis bagi vaksin DPT asal menyumbang sebahagian besar kesan sampingan tempatan dan sistemik yang kecil pada kebanyakan bayi yang divaksin (seperti demam ringan atau sakit di tapak suntikan). Vaksin aselular yang lebih baharu, yang dikenali sebagai DTaP, telah banyak mengurangkan kejadian kesan buruk berbanding vaksin pertusis "sel keseluruhan" yang terdahulu, namun imuniti berkurangan lebih cepat selepas vaksin asel berbanding vaksin seluruh sel. [15] [16]

Antara 10% dan 50% orang yang diberi vaksin seluruh sel mengalami kemerahan, bengkak, sakit atau kelembutan di tapak suntikan dan/atau demam, kurang daripada 1% mengalami sawan demam atau menangis dalam tempoh yang lama, dan kurang daripada 1 daripada setiap 1,000 hingga 2,000 orang yang diberi vaksin mempunyai episod hipotonik-hiporesponsif. [1] Tindak balas yang sama mungkin berlaku selepas vaksin aselular, tetapi kurang biasa. [17] Kesan sampingan dengan kedua-dua jenis vaksin, tetapi terutamanya vaksin seluruh sel, lebih berkemungkinan semakin besar kanak-kanak itu. [1] Vaksin seluruh sel tidak boleh digunakan selepas umur tujuh tahun. [1] Menurut WHO, masalah neurologi jangka panjang yang serius tidak dikaitkan dengan mana-mana jenis. [1] WHO mengatakan bahawa satu-satunya kontraindikasi kepada vaksin pertusis sel keseluruhan atau aselular ialah tindak balas anafilaksis terhadap dos vaksin pertusis sebelumnya, [1] manakala Pusat Kawalan dan Pencegahan Penyakit (CDC) AS menyenaraikan ensefalopati bukan disebabkan oleh satu lagi punca yang boleh dikenal pasti berlaku dalam masa tujuh hari selepas dos vaksin pertusis sebelumnya sebagai kontraindikasi dan mengesyorkan mereka yang pernah mengalami sawan, mempunyai gangguan neurologi yang diketahui atau disyaki, atau mengalami kejadian neurologi selepas dos sebelumnya tidak diberi vaksin sehingga selepas rawatan dimulakan dan keadaan menjadi stabil. [17] Hanya vaksin aselular digunakan di AS. [17]

Vaksin pertusis sel penuh mengandungi keseluruhan organisma yang tidak aktif manakala vaksin pertusis acellular mengandungi bahagian (subunit) termasuk toksin pertusis sahaja atau dengan komponen seperti haemagglutinin berfilamen, antigen fimbrial dan pertactin. [18]

Sehingga 2018 [kemas kini] , terdapat empat vaksin DTaP/Tdap aselular yang dilesenkan untuk digunakan di Amerika Syarikat: Infanrix dan Daptacel – untuk kanak-kanak, Boostrix dan Adacel – untuk remaja dan dewasa. [17]

Komposisi komponen pertusis vaksin terpilih [19]
Vaksin Penerbit Dilesenkan untuk Toksin pertusis (PT), μg Hemagglutinin berfilamen (FHA), μg Pertactin (PRN), μg Fimbriae (FIM), μg
Infanrix GlaxoSmithKline 6 minggu hingga 7 tahun 25 25 8
Boostrix GlaxoSmithKline lebih tua daripada 10 tahun 8 8 2.5
Daptacel Sanofi Pasteur 6 minggu hingga 7 tahun 10 5 3 5
Adacel Sanofi Pasteur 11 hingga 64 tahun 2.5 5 3 5

Pearl Kendrick, Loney Gordon dan Grace Eldering mempelajari pertusis pada tahun 1930-an. [20] Mereka membangunkan dan menjalankan kajian skala besar pertama tentang vaksin yang berjaya untuk penyakit itu. [20]

Vaksin pertusis biasanya diberikan sebagai komponen vaksin difteria-tetanus-pertussis (DTP/DTwP, DTaP dan Tdap). Terdapat beberapa jenis vaksin difteria-tetanus-pertussis. Vaksin pertama terhadap pertusis telah dibangunkan pada tahun 1930-an oleh pakar kanak-kanak Leila Denmark. Ia termasuk seluruh sel yang dibunuh Bordetella pertussis bakteria. Sehingga awal tahun 1990-an ia digunakan sebagai sebahagian daripada vaksin DTwP untuk imunisasi kanak-kanak. Walau bagaimanapun, ia mengandungi endotoksin pertussis (lipoligosaccharide permukaan) dan menghasilkan kesan sampingan. [21]

Vaksin pertusis aselular baharu telah dibangunkan pada tahun 1980-an, yang mengandungi hanya beberapa antigen pertusis terpilih (toksin dan perekat). [21] Vaksin aselular kurang berkemungkinan menimbulkan kesan sampingan. [22] Mereka menjadi sebahagian daripada vaksin DTaP untuk kanak-kanak. [21] Pada tahun 2005, dua produk vaksin baharu telah dilesenkan untuk kegunaan remaja dan dewasa yang menggabungkan toksoid tetanus dan difteria dengan vaksin pertusis aselular. [23] Vaksin (Tdap) ini mengandungi jumlah antigen pertusis yang berkurangan berbanding dengan vaksin DTaP. [19]

Kontroversi pada 1970-an-1980-an Sunting

Pada tahun 1970-an dan 1980-an, kontroversi tercetus berkaitan persoalan sama ada komponen pertusis seluruh sel menyebabkan kecederaan otak kekal dalam kes-kes yang jarang berlaku, dipanggil encephalopathy vaksin pertusis. Di sebalik dakwaan ini, doktor mengesyorkan vaksin kerana manfaat kesihatan awam yang luar biasa, kerana kadar yang dituntut adalah sangat rendah (satu kes bagi setiap 310,000 imunisasi, atau kira-kira 50 kes daripada 15 juta imunisasi setiap tahun di Amerika Syarikat), dan risiko kematian akibat penyakit itu adalah tinggi (pertusis membunuh ribuan rakyat Amerika setiap tahun sebelum vaksin diperkenalkan). [24] Tiada kajian menunjukkan hubungan sebab akibat, dan kajian kemudian menunjukkan tiada hubungan apa-apa jenis antara vaksin DPT dan kecederaan otak kekal. Kerosakan otak akibat vaksin yang didakwa terbukti sebagai keadaan yang tidak berkaitan, epilepsi bayi. [25] Pada tahun 1990, the Jurnal Persatuan Perubatan Amerika memanggil perkaitan itu sebagai "mitos" dan "karut". [26]

Walau bagaimanapun, publisiti negatif dan ketakutan menyebabkan kadar imunisasi jatuh di beberapa negara, termasuk UK, Sweden, dan Jepun. Peningkatan dramatik dalam kejadian pertusis diikuti. [27]

Di Amerika Syarikat, margin keuntungan yang rendah dan peningkatan dalam tindakan undang-undang berkaitan vaksin menyebabkan banyak pengeluar berhenti mengeluarkan vaksin DPT pada awal 1980-an. [24] Pada tahun 1982, dokumentari televisyen DPT: Rolet Vaksin oleh wartawan Lea Thompson menggambarkan kehidupan kanak-kanak yang kecacatan teruk mereka salah dipersalahkan pada vaksin DPT. [28] Publisiti negatif seterusnya membawa kepada banyak tindakan undang-undang terhadap pengeluar vaksin. [29] Menjelang 1985, pengeluar vaksin mengalami kesukaran mendapatkan insurans liabiliti. Harga vaksin DPT melambung tinggi, menyebabkan penyedia mengehadkan pembelian, mengehadkan ketersediaan. Hanya satu pengeluar kekal di AS menjelang akhir tahun 1985. Sebagai tindak balas, Kongres meluluskan Akta Kecederaan Vaksin Kanak-kanak Kebangsaan (NCVIA) pada tahun 1986, mewujudkan sistem tanpa kesalahan persekutuan untuk memberi pampasan kepada mangsa kecederaan yang disebabkan oleh vaksin yang disyorkan. [30]


Bahan-bahan Vaksin dan Maklumat Pengilang

Kami telah menyenaraikan bahan vaksin (bahan yang muncul dalam produk vaksin akhir), bahan proses (bahan yang digunakan untuk mencipta vaksin yang mungkin atau mungkin tidak muncul dalam produk vaksin akhir), dan medium pertumbuhan (vaksin bahan ditanam) untuk vaksin yang diluluskan oleh Pentadbiran Makanan & Ubat (FDA) dan lazimnya disyorkan oleh Pusat Kawalan Penyakit (CDC.) Produk kontroversi yang digunakan untuk membuat vaksin: sel African Green Monkey (Vero), aluminium, produk lembu, sel Cocker Spaniel, formaldehid, sel tisu paru-paru janin manusia, produk serangga dan otak tikus.

Walaupun tidak disenaraikan, setiap vaksin mengandungi strain virus yang sedang divaksinasi. Setiap kemasukan vaksin dipautkan ke sisipan pakej pengilang yang mengandungi maklumat tentang dos, kuantiti ramuan dan cara vaksin dibuat. Sesetengah vaksin, seperti vaksin influenza, sering diubah suai dan anda mungkin ingin berunding dengan sisipan pakej dalam talian dan doktor anda untuk mendapatkan maklumat terkini.

I. VAKSIN DAN BAHAN
1. Adenovirus18. Influenza A & B
2. Antraks19. Japanese Encephalitis
3. BCG (tuberkulosis)20. Meningokokus
4. taun21. Campak
5. DT (difteria & tetanus)22. MMR (measles, mumps, & rubella)
6. DTap (difteria, tetanus, & pertusis)23. Pneumokokal
7. DTap-IPV (difteria, tetanus, pertusis, & polio)24. Polio
8. DTap-HepB-IPV (difteria, tetanus, pertusis, hepatitis B, & polio)25. Rabies
9. DTap-IPV/Hib (difteria, tetanus, pertusis, polio, & haemophilus influenzae jenis B)26. Rotavirus
10. Hib (haemophilus influenzae jenis B)27. Rubella
11. Hib/Hep B (haemophilus influenzae jenis B & hepatitis B)28. Cacar
12. Hep A (hepatitis A)29. TD (tetanus & difteria)
13. Hep B (hepatitis B)30. Tdap (tetanus, difteria, & pertusis)
14. Hep A/Hep B (hepatitis A & hepatitis B)31. Kepialu
15. HPV (human papillomavirus)32. Varicella (cacar air)
16. Influenza A (H1N1) (selesema babi)33. Demam Kuning
17. Influenza A (H5N1) (selesema burung)34. Zoster (kayap)
1. Vaksin Adenovirus
NAMA SESUAI
PENGELUAR
(klik untuk sisipan pakej)
NAMA SESUAI
TARIKH MASUKKAN PAKEJ

II. GLOSARI DAN BUTIRAN UNTUK BAHAN

"Serum lembu adalah hasil sampingan industri daging. Darah lembu boleh diambil semasa penyembelihan, daripada lembu dewasa, anak lembu, anak lembu yang sangat muda atau (apabila lembu yang disembelih kemudiannya didapati hamil) daripada janin lembu. Ia juga diperoleh daripada apa yang dipanggil haiwan 'penderma', yang memberikan darah lebih daripada sekali.

Darah boleh didapati daripada janin lembu hanya kerana sebahagian daripada haiwan betina yang disembelih untuk daging untuk kegunaan manusia didapati (selalunya tanpa diduga) hamil.

Blood is available from very young calves because calves, especially males from dairy breeds, are often slaughtered soon, but not necessarily immediately, after birth because raising them will not be economically beneficial. Older animals are, of course, slaughtered for meat.

Only donor cattle are raised for the purpose of blood donation. Donor cattle are invariably kept in specialized, controlled herds. Blood is taken from these animals in a very similar way to that used for human blood donation.

Irrespective of whether blood is taken at slaughter or from donors, the age of the animal is an important consideration because it impacts the characteristics of the serum.

Acumedia Manufacturers, “Mueller Hinton Agar (7101),” www.neogen.com, June 2011 Atlanta Biologicals, “Earle’s Balanced Salt Solution (EBSS),” www.atlantabio.com, 2010

CDC, “Basics and Common Questions: Ingredients of Vaccines – Fact Sheet,” www.cdc.gov, Feb. 22, 2011

FDA, “Vaccines Licensed for Immunization and Distribution in the US with Supporting Documents,” www.fda.gov, Aug. 29, 2016

Health Protection Agency, “General Cell Collection: MDCK,” www.hpacultures.org.uk, 2011

G.M. Healy, S. Teleki, A.V. Seefried, M.J. Walton, and H.G. Macmorine, “Improved Chemically Defined Basal Medium (CMRL-1969) for Primary Monkey Kidney and Human Diploid Cells,” Mikrobiologi Gunaan dan Alam Sekitar, www.aem.asm.org, 1971

International Serum Industry Association, “FAQ,” www.serumindustry.org/faq, 2013

Pontifical Academy for Life, “Moral Reflections on Vaccines Prepared From Cells Derived From Aborted Human Foetuses,” www.immunize.org/concerns/vaticandocument.htm, June 9, 2005

Rebecca Sheets, “History and Characterization of the Vero Cell Line,” www.fda.gov, May 12, 2000

Sigma-Aldrich, “DMEM,” www.sigmaaldrich.com, 2013

Alison Weiss, “The Genus Bordetella,” The Prokaryotes: A Handbook on the Biology of Bacteria,” Ed. Martin M. Dworkin, Stanley Falkow, Karl-Heinz Schleifer, and Erko Stackebrandt, 2006.


Examples of Vaccine Production

Inactivated Virus (Influenza)

Influenza virus vaccine for intramuscular use is a sterile suspension prepared from influenza viruses propagated in chicken embryos. This vaccine is the primary method for preventing influenza and its more severe complications. 13

Typically, influenza vaccine contains two strains of influenza A viruses (H1N1 and H3N2) and a single influenza B virus. An additional strain of the influenza B virus was added, with the first four-antigen-containing-vaccine licensed in 2012. 14 The two type A viruses are identified by their subtypes of hemagglutinin and neuraminidase. The hemagglutinin and neuraminidase glycoproteins of influenza A virus comprise the major surface proteins and the principal immunizing antigens of the virus. These proteins are inserted into the viral envelopes as spike-line projections in a ratio of approximately 4 :𠂑. 15

The trivalent subunit vaccine is the predominant influenza vaccine used today. This vaccine is produced from viral strains that are identified early each year by the World Health Organization, the Centers for Disease Control and Prevention (CDC), and CBER. For U.S.-licensed manufacturers, the viral strains are normally acquired from CBER or CDC. European strains are typically provided by the National Institute for Biological Standards and Control, and Southern Hemisphere strains by the Therapeutic Goods Administration of Australia. These viral strains are used to prepare cells banks at each manufacturer, which cell banks are ultimately used as the inoculums for vaccine production.

The substrate most commonly used by producers of influenza vaccine is the 11-day-old embryonated chicken egg. A monovalent virus (suspension) is received from CBER or the CDC. The monovalent virus suspension is passed in eggs. The inoculated eggs are incubated for a specific time and temperature regimen under controlled relative humidity and then harvested. In the European Union, the number of passages from the original sample is limited. The harvested allantoic fluids, which contain the live virus, are tested for infectivity, titer, specificity, and sterility. These fluids are then stored wet frozen at extremely low temperatures to maintain the stability of the monovalent seed virus (MSV). 16 This MSV is also certified by CBER.

Once the MSV is introduced into the egg by automated inoculators, the virus is grown at incubated temperatures, and then the allantoic fluid is harvested and purified by high-speed centrifugation on a sucrose gradient or by chromatography. The purified virus is often split using a detergent before final filtration. The virus is inactivated using formaldehyde before or after the primary purification step, depending on the manufacturer. This is repeated for three or four strains of virus, and the individually tested and released inactivated viral concentrates are combined and diluted to final vaccine strength. Fig. 5.2 outlines the overall process.

Egg-based influenza vaccine manufacturing process flow.

CBER, Center for Biologics Evaluation and Research (of the U.S. Food and Drug Administration) QA, quality assurance QC, quality control.

The inactivated virus vaccine described above is used for the majority of flu vaccine produced and sold today. In recent years, the inactivated influenza vaccine produced on mammalian cell culture has been approved in a number of countries. The process replaces the egg-based virus expansion with a certified cell line the downstream processes are similar, but focused on removing the host cell protein and DNA to below designated thresholds. A recombinant influenza vaccine, produced in insect cells infected with a recombinant baculovirus to express the hemagglutinin protein has also been approved in the United States.

Recombinant Protein (Hepatitis B)

In July 1986, a recombinant hepatitis B vaccine was licensed in the United States. This vaccine built on the knowledge that heat-inactivated serum containing hepatitis B virus (HBV) and hepatitis B surface antigen (HBsAg) was not infectious, but was immunogenic and partially protective against subsequent exposure to HBV. 17 HBsAg was the component that conferred protection to HBV on immunization. 18 To produce this vaccine, the gene coding for HBsAg, or “S” gene, was inserted into an expression vector that was capable of directing the synthesis of large quantities of HBsAg in Saccharomyces cerevisiae. The HBsAg particles expressed by and purified from the yeast cells have been demonstrated to be equivalent to the HBsAg derived from the plasma of the blood of hepatitis B chronic carriers. 17 , 19 , 20

The recombinant S. cerevisiae cells expressing HBsAg are grown in stirred tank fermenters. The medium used in this process is a complex fermentation medium that consists of an extract of yeast, soy peptone, dextrose, amino acids, and mineral salts. In-process testing is conducted on the fermentation product to determine the percentage of host cells with the expression construct. 7 At the end of the fermentation process, the HBsAg is harvested by lysing the yeast cells. It is separated by hydrophobic interaction and size-exclusion chromatography. The resulting HBsAg is assembled into 22-nm𠄽iameter lipoprotein particles. The HBsAg is purified to greater than 99% for protein by a series of physical and chemical methods. The purified protein is treated in phosphate buffer with formaldehyde, sterile filtered, and then coprecipitated with alum (potassium aluminum sulfate) to form bulk vaccine adjuvanted with amorphous aluminum hydroxyphosphate sulfate. The vaccine contains no detectable yeast DNA but may contain not more than 1% yeast protein. 7 , 19 , 21 In a second recombinant hepatitis B vaccine, the surface antigen expressed in S. cerevisiae cells is purified by several physiochemical steps and formulated as a suspension of the antigen absorbed on aluminum hydroxide. The procedures used in its manufacturing result in a product that contains no more than 5% yeast protein. No substances of human origin are used in its manufacture. 20 Vaccines against hepatitis B prepared from recombinant yeast cultures are noninfectious 20 and are free of association with human blood and blood products. 19

Each lot of hepatitis B vaccine is tested for safety, in mice and guinea pigs, and for sterility. 19 QC product testing for purity and identity includes numerous chemical, biochemical, and physical assays on the final product to assure thorough characterization and lot-to-lot consistency. Quantitative immunoassays using monoclonal antibodies can be used to measure the presence of high levels of key epitopes on the yeast-derived HBsAg. A mouse potency assay is also used to measure the immunogenicity of hepatitis B vaccines. The effective dose capable of seroconverting 50% of the mice (ED50) is calculated. 21

Hepatitis B vaccines are sterile suspensions for intramuscular injection. The vaccine is supplied in four formulations: pediatric, adolescent/high-risk infant, adult, and dialysis.

All formulations contain approximately 0.5 mg of aluminum (provided as amorphous aluminum hydroxyphosphate sulfate) per milliliter of vaccine. 19 Table 5.2 summarizes the QC testing requirements for the release of recombinant hepatitis B vaccine.

TABLE 5.2

Testing Requirements for the Release of Recombinant Hepatitis B Vaccine

Type of TestStage of Production
Plasmid retentionFermentation production
Purity and identityBulk-adsorbed product or nonadsorbed bulk product
SterilityFinal bulk product
SterilityFinal container
General safetyFinal container
PyrogenFinal container
KesucianFinal container
PotencyFinal container

Most vaccines are still released by CBER on a lot-by-lot basis but for several extensively characterized vaccines, such as hepatitis B and human papillomavirus (HPV) vaccines, which are manufactured using recombinant DNA processes, this requirement has been eliminated.. Their manufacturing process includes significant purification, and they are extensively characterized by their analytical methods. In addition, hepatitis B vaccine had to demonstrate a “track record” of continued safety, purity, and potency to qualify for this exemption. 7 , 22

Conjugate Vaccine (Haemophilus influenzae Type B)

Pengeluaran daripada Haemophilus influenzae type b (Hib) conjugate includes the separate production of capsular polysaccharide from Hib and a carrier protein such as tetanus protein from Clostridium tetani (i.e., purified tetanus toxoid), CRM protein from Corynebacterium diphtheriae, or outer membrane protein complex of Neisseria meningitidis.

The capsular polysaccharide is produced in industrial bioreactors using approved seeds of Hib. A crude intermediate is recovered from fermentation supernatant, using a cationic detergent. The resulting material is harvested by continuous-flow centrifugation. The paste is then resuspended in buffer, and the polysaccharide is selectively dissociated from disrupted paste by increasing the ionic strength. The polysaccharide is then further purified by phenol extraction, ultrafiltration, and ethanol precipitation. The final material is precipitated with alcohol, dried under vacuum, and stored at �ଌ for further processing.

Tetanus protein is prepared in bioreactors using approved seeds of C. tetani. The crude toxin is recovered from the culture supernatant by continuous-flow centrifugation and diafiltration. Crude toxin is then purified by a combination of fractional ammonium sulfate precipitation and ultrafiltration. The resulting purified toxin is detoxified using formaldehyde, concentrated by ultrafiltration, and stored at between 2ଌ and 8ଌ for further processing.

The industrial conjugation process was initially developed using tetanus toxoid by a team headed by J.B. Robbins at the National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland. 23

Conjugate preparation is a two-step process that involves: (a) activation of the Hib capsular polysaccharide and (b) conjugation of activated polysaccharide to tetanus protein through a spacer. Activation includes chemical fragmentation of the native polysaccharide to a specified molecular weight target and covalent linkage of adipic acid dihydrazide. The activated polysaccharide is then covalently linked to the purified tetanus protein by carbodiimide-mediated condensation using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide. Purification of the conjugated material is performed to obtain high-molecular-weight conjugate molecules devoid of chemical residues and free protein and polysaccharide. Conjugate bulk is then diluted in an appropriate buffer, filled into unit-dose and/or multidose vials, and lyophilized.

Live Attenuated Vaccine (Measles)

The measles virus, isolated in 1954, is part of the genus Morbillivirus in the family Paramyxoviridae. Current vaccines are derived from Edmonston, Moraten, or Schwarz strains. Such vaccines have been on the market since the 1960s and in combination (measles, mumps, rubella [MMR]) since the 1970s. The final vaccine is a live attenuated viral vaccine inducing immunity in more than 90% of recipients.

For one measles vaccine, the manufacture of the vaccine starts with specific pathogen-free embryonated chicken eggs that are incubated several days. The embryos are collected and treated with trypsin to prepare the chick embryo fibroblasts for cell culture. All of the operations are done under strict aseptic conditions, performed by well-trained operators.

Cell culture are grown in roller bottles using fetal calf sera and M199 Hanks media for optimal cell growth. Chick embryo fibroblast cells are further infected by the viral working seed and incubated several days for viral culture. At the end of the viral culture, the cells are disrupted by mechanical lysis to release the virus. The virus is purified by centrifugation and filtration and stored frozen. After release of all QC tests, the vaccine is formulated alone or with mumps and rubella vaccines and lyophilized to obtain the stable product. The vaccine is reconstituted just before use.

Other manufacturers use different cell substrates for example, the Serum Institute of India uses human diploid cells to manufacture their measles vaccine (see http://www.seruminstitute.com/content/products/product_mvac.htm).

Virus-Like Particle�sed Vaccines

Traditional viral vaccines rely on attenuated virus strains or inactivation of infectious virus. Subunit vaccines based on viral proteins expressed in heterologous systems have been effective for some pathogens, but have often had poor immunogenicity because of incorrect folding or modification. 24 Virus-like particles (VLPs) are designed to mimic the overall structure of virus particles and, thus, preserve the native antigenic conformation of the immunogenic proteins. VLPs have been produced for a wide range of taxonomically and structurally distinct viruses and have unique potensi advantages in terms of safety and immunogenicity over previous approaches. 1 Attenuation or inactivation of the VLP is not required this is particularly important as epitopes are commonly modified by inactivation treatments. 25 However, if a viral vector (e.g., baculovirus) is used as the expression system, inactivation may be required if the purification process cannot eliminate residual viral activity.

For a VLP to be a realistic vaccine candidate, it needs to be produced in a safe expression system that is easy to scale up to large-scale production 1 and by an accompanying purification and inactivation process that will maintain native structure and immunogenicity and will meet the requirements of today's global regulatory authorities. A number of expression systems manufacture multimeric VLPs, including the baculovirus expression system (BVES) in Sf9 and High Five cells, Escherichia coli, Aspergillus niger, Chinese hamster ovary cells, human function liver cells, baby hamster kidney cells, transgenic plants (potato, tobacco, soybean), S. cerevisiae, Pichia pastoris, human embryonic kidney 293 (HEK293) cells, and lupin callus (a plant-cell production system) with yields ranging from 0.3 to 10 µg/mL or as high as 300 to 500 µg/mL with E coli and HEK293 (purified). 2

The BVES has proven quite versatile, demonstrating the capability of preparing vaccine candidates for papillomavirus, feline calicivirus, hepatitis E virus, porcine parvovirus, chicken anemia virus, porcine circovirus, SV40 (simian virus 40), poliovirus, bluetongue virus, rotavirus, hepatitis C virus, HIV, simian immunodeficiency virus, feline immunodeficiency virus, Newcastle disease virus, severe acute respiratory syndrome (SARS) coronavirus, Hantaan virus, influenza A virus, and infectious bursal disease virus. 1

Many pathogenic viruses, such as influenza, HIV, and hepatitis C, are surrounded by an envelope, a membrane that consists of a lipid bilayer derived from the host cell, inserted with virus glycoprotein spikes. These proteins are targets of neutralizing antibodies and are essential components of a vaccine. Owing to inherent properties of the lipid envelope, assembly of VLPs in insect cells for these viral vaccines is a different type of technical challenge to those produced viruses with multiple capsids. 1 For these targets, production of VLPs is a challenging task because the synthesis and assembly of one or more recombinant proteins may be required. This is the case for VLPs of rotavirus, which is an RNA virus with capsids formed by 1860 monomers of four different proteins. In addition, the production of most VLPs requires the simultaneous expression and assembly of several recombinant proteins, which, in the case of RLP, needs to occur in a single host cell. 26 Purification of VLPs also constitutes a particularly challenging task. VLPs are structures of several nanometers in diameter and of molecular weights in the range of 10 6 �. Also, for guaranteeing the quality of the product, it is not sufficient to demonstrate the absence of contaminant proteins it is also necessary to show that proteins are correctly assembled into VLPs.

Production of HPV VLPs represents another challenge. The HPV type 16 major 55-kDa capsids protein, L1, when produced in certain recombinant expression systems such as S. cerevisiae, can form irregularly shaped VLPs with a broad size distribution. These HPV VLPs are inherently unstable and tend to aggregate in solution. The primary challenge of HPV vaccine formulation development was the preparation of aqueous HPV VLP solutions that are stable under a variety of purification, processing, and storage conditions. By treating the HPV VLPs through a process of disassembly and reassembly, the stability and in vitro potency of the vaccine are enhanced significantly. In addition, the in vivo immunogenicity of the vaccine was also improved by as much as approximately 10-fold, as shown in mouse potency studies. 27 The disassembly and reassembly of particles may also be important to remove residual proteins from the expression system or host cells used in the production and is a serious processing challenge, particularly for enveloped VLPs.


Vaksin

Q. Do Vaccines cause Autism? I have heard all over the news lately that the vaccines we give our children can cause Autism. Adakah ini benar? Is it dangerous? Should I vaccinate my one year old son?

Andrew Wakefield MD started the controversy when publish the idea in Lancet. He was paid 130,000 dollars to lie

Check this link for full story:
http://www.thedoctorsvideos.com/video/749/MMR-and-Autism-The-Andrew-Wakefield-Story

Q. Who Should Receive the Flu Vaccine? Should I go get vaccinated for the flu? I have been told it is advised only for certain people, so who should receive this vaccine?

A. before you would like to go on with any vaccination, you should check out this very long list of links and create your own opinion:

at the bottom you will also find links in english. vaccinations in general are very disputable/dubious and it is probably time that we learn about it.

Q. Does the flu vaccine protect from all kinds of flu? If I get a flu vaccine does that mean I am completely protected from getting the flu?


Vaccine Testing from Discovery to Production

One of the key challenges of effectively developing a vaccine is understanding the immune correlates of protection (1,2) . Vaccine development leads to improvements in antigen and adjuvant selection and the design of better vectors – all of which contribute to the success of a vaccine candidate, while keeping appropriate safety testing in mind. It requires appropriate pre-clinical models, testing methodologies, and the availability of necessary immunology tools.

We have decades of experience supporting the vaccine industry with a specific and unique range of products and related services. Our global network of scientific, technical, and regulatory experts provides vaccine developers with the right expertise early in the development process to boost productivity, efficiency, and profitability, and get the safest and most effective vaccines to market.

(1) The current challenges for vaccine development. Oyston, Robinson J Med Microbiol. 2012 Jul61(Pt 7):889-894. doi: 10.1099/jmm.0.039180-0. Epub 2012 Feb
(2) Challenges and responses in human vaccine development. Stefan HE Kaufmann and all. Current Opinion in Immunology Volume 28, June 2014, Pages 18-26

What’s the Best Approach to Designing a Vaccine?

A vaccine is defined as a biological preparation that stimulates active acquired immunity against a certain disease or pathogen by being an agent that represents the disease-causing microorganism. It’s often made from a weakened or killed form of the microorganism, its toxins, or one of its surface protein antigens. Scientists take many approaches to design vaccines against a pathogenic microorganism. These choices are dictated by the nature of pathogen and the infection, as well as practical considerations about the use of the vaccine. Some of the options include live attenuated, inactivated, DNA, and recombinant subunit vaccines.

Our experts are here to help you figure out the best type of vaccine to develop, design the best path to develop it, and manufacturing it – all while being mindful of all necessary regulatory guidelines.

Where Are You in Your Vaccine Development?

Our services and expertise can help clients meet appropriate regulatory requirements around clinical trials by initiating and completing critical phases of preclinical development by designing, performing, and documenting safety tests. We can also support your strategy that covers early development through to market.

Browse our vaccine development services by clicking the tabs below:

It is important to research and eliminate unsuccessful programs through secara in vitro dan dalam vivo techniques to find your leading candidate. Our unmatched knowledge of animal models, safety testing, infectious diseases, and immunology will help you select the most promising vaccine candidates and provide the information clients need to develop better vaccines.

From Vaccine Dalam Vitro Assays to Dalam Vivo model

Find the best bacterial models to use in your drug development program, from early secara in vitro screening assays to identify efficacy, to a range of clinically relevant dalam vivo model.

Dalam Vitro Immune Profiling Assays for Vaccine and Adjuvants Development

The first step in developing your vaccine will be to determine its immunogenicity secara in vitro. We can test the ability of your novel vaccine antigens to invoke an immune response with our human and animal cell cultures. Our dedicated cell biology team use state-of-the-art methods to not only assess cell proliferation and activation, but also to characterize the nature of the immune response to your antigens.

    • Screening peptide/antigen/live viruses
    • Dalam vitro immunogenicity assays
    • Testing of novel adjuvants and antigen delivery vectors

    Dalam Vivo Immunogenicity Testing

    We can help you take your novel vaccine formulations dalam vivo testing their ability to stimulate T and B cell responses using different delivery routes. We provide data to help you assess the relative potencies of your different formulations by characterizing and quantifying the antibodies produced and characterizing the magnitude and the nature of the T cell response.

    Challenge and Protection Studies for Vaccine and Adjuvants

    As the ultimate test of your vaccine, we do vaccine efficacy testing using a wide range of infection models and have the capacity to develop models specific to your needs. Disease-specific models of bacterial and viral infection, such as influenza models or respiratory syncytial virus models (RSV).

    Infection is measured by clinical disease scores, viral titers, bacterial CFU, and histopathology. We also take immunological readouts pre-infection of antibody levels (IgG, IgG1, IgG2a), HAI, CTL, and lung cytokines. Combining clinical disease with immunological readouts gives a direct comparison between immunogenicity and efficacy of your vaccine.

    Ex Vivo Read Out:

      • Viral titers or bacterial CFU (the extent of bacterial infection can also be monitored in-life using luminescent strains of bacteria via IVIS imaging)
      • Histopathology
      • Cell-based assays
      • Cytotoxicity assays
      • Immune modulation assays (ELISA, Luminex, FACS, ELISpot)
        • Antibody levels
        • HAI
        • Cytokines (systemic, tissue specific)
        • T cell, B cell, and immune cell subset characterization

        Need help to select the optimimal assay between secara in vitro dan dalam vivo models for your adjuvants and vaccine development?

        Vaccine development follows a strict regulatory pathway, of which safety assessment is a critical component. In addition, study designs and interpreting the subsequent data are also important considerations. The type of studies depends on what type of vaccine you’re developing.

        It’s important to select a laboratory that can provide key technical expertise and experience in handling these types of products to run these studies successfully and support critical data interpretation. Studies can be conducted in accordance to Good Laboratory Practice (GLP) as applicable:

        Vaccine Safety Testing Considerations

        Vaccines follow a strict regulatory pathway and the safety assessment is a critical component. The type of studies conducted depend on the vaccine type and it is due to their diversity that they require a case by case approach.

        Module 2: Nonclinical Studies

          • Efficacy including vaccine immunogenicity testing and CDC-approved quarantine
          • Local/systemic studies
          • Immunopharmacology
          • Vector-shedding studies and biodistribution

          Module 3: CMC Quality and Lot Release Testing

            • Tumorigenicity
            • Potency and dose response
            • Neurovirulence safety testing

            Speed Up Your Vaccine Efficacy and Safety Testing

            There are many components to consider to effectively develop a vaccine. Learn about the regulatory guidelines, study designs, and endpoints you should consider to efficiently and effectively develop your vaccine from discovery to safety assessment.

            Additional scientific expertise includes:

              • Assessment of neutralizing antibodies - nAb
              • Measurement of the humoral and cellular immune response by ELISpot and by flow cytometry (mainly looking at the activation of specific cell types)
              • Measurement of specific biomarkers (e.g., CRP, cytokines)
              • Infectivity and titer for vaccines

              Laboratory Support Products and Services

              Want to know how to Speed Up Your Vaccine Efficacy and Safety Testing?

              Charles River Laboratories can expedite vaccine development programs from manufacturing for early-phase clinical trials to lot release for commercial products. We have more than 20 years of experience of virus and vaccine manufacturing along with providing the associated testing to ensure product safety and efficacy. These development services are accompanied by our scientific and regulatory experience, which allows us to predict and eliminate potential pitfalls early in development while ensuring compliance with all applicable international regulatory standards.

              Manufacturing Support

              Testing Support

              • Adjuvant assessment
              • Immunogenicity and immunopotency assays
              • Dose-ranging studies
              • Tumorgenicity/oncogenicity testing

              Have more questions about vaccine manufacturing and support services?

              Frequently Asked Questions (FAQs) about Vaccine Development Services

              Vaccines are medicinal agents intended to elicit an immune response by increasing antibody production and/or specific T cell responses. It has led to the reduction and eradication of key infectious diseases globally, including smallpox. The first successful case of vaccination was performed by Edward Jenner in 1796. He was the first to observe that individuals who caught cowpox did not contract smallpox, even when coming in direct contact with the disease.

              An individual that has been vaccinated produces antibodies against the protein antigen that protect him/her from contracting the disease when attacked by the pathogenic microorganism.

              This vaccine can compromise a wide range of different type of subunits, typically viral proteins, protein components, or even peptides of pathogens. Other type of subunit vaccines, like toxoids and bacterial polysaccharides, are detailed separately. They are typically safer and can be manufactured in a well-controlled process.

              Viral antigens suitable to induce protective immunity against infection can be isolated from viral particles but are increasingly produced using recombinant DNA technologies. Most purified antigens have limited intrinsic immunogenicity so they, as with subunit vaccines, usually need multiple doses and the incorporation of an adjuvant during vaccine development to induce both antibody-mediated and cellular immunity.

              Recombinant antigens are produced in yeast, microbial, and mammalian cell lines in well-established processes with a proven safety profile and batch-to-batch consistency.

              Some viruses, like human papillomavirus (HPV) or hepatitis B, cannot be grown in in vitro culture systems to high titers, and subunit vaccines, derived through antigen isolation or recombinant technologies, are now preferred for vaccine manufacturing.

              Live recombinant bacteria or viral vectors effectively stimulate the immune system like natural infections and have intrinsic adjuvant properties. The use of recombinant proteins allows for the targeting of immune responses focused against few protective antigens as platforms to deliver vaccine antigens and as immunotherapeutic agents to specifically target and kill cancer cells. However, one of the main challenges in developing vaccines for these new strategies of immunization consists of designing vaccines that elicit the appropriate kind of immune response to confer immunity, mainly to intracellular pathogens and especially to those that establish chronic, often lifelong, infections. 1

              Generally, the recombinant antigens that are delivered either as DNA plasmids or subunit proteins are reasonably safe. In contrast, replicating viral vectors are often highly immunogenic, but they also carry the risk of recombination, reversion to virulence, and pathogenesis during vaccine development.

              Vaccines can be composed of polysaccharide (sugar) molecules found on the outside layer of encapsulated bacteria, such as 23 Streptococcus pneumoniae (pneumococcal). There are several challenges to be aware of during this vaccine development, including the behavior of bacterial structure, capsule switching, the immune response of the host, and cost.

              Purified inactivated viruses have been traditionally used for vaccine development, and such vaccines have proven to be safe and effective for the prevention of diseases caused by viruses like influenza virus and poliovirus.

              Inactivated viral vaccines contain purified whole bacteria or viruses which have been killed, typically by chemicals like beta-propiolactone or formaldehyde. Inactivated vaccines usually don’t require refrigeration, and they can be easily stored and transported in a freeze-dried form, which makes them more accessible to people in developing countries. Killed vaccines are generally less immunogenic than live attenuated vaccines. As a result, they are commonly administered with an adjuvant (e.g., aluminum salts) to augment their immunogenicity.

              A few examples of inactivated viral are influenza viruses, rabies viruses, hepatitis A viruses and whole-cell Bordetella pertussis vaccine.

              Live attenuated vaccines contain whole bacteria or viruses which have been “weakened” to create a protective immune response, but do not affect healthy people.

              Live vaccines tend to create a strong and lasting immune response. However, they aren’t suitable for people with a compromised immune system, either due to drug treatment or underlying illness, because the weakened viruses or bacteria can multiply too quickly and lead to disease.

              Live attenuated vaccines against human viral diseases have been amongst the most successful, cost-effective interventions in medical history. This kind of vaccine development functions well for acute diseases such as smallpox, poliomyelitis, and measles. However, it may not function well to treat chronic infections like HIV due to challenges with safety and efficacy.

              A toxoid is an inactivated native toxin that has lost its ability to cause disease but has retained a reduced amount of immunogenicity. Two well-known toxoid vaccines include the diphtheria-derived toxoid and tetanus toxoid. Their reduced immunogenicity means these types of vaccines often require an immunogenic boost with the addition of an adjuvant.

              Identifying and assessing the best vaccine adjuvants are key to developing a plan for this vaccine in immunogenicity studies, as well as their safety. The characterization and potency testing of a toxoid vaccine development is critical, including lethal and intradermal challenge studies to ensure inactivation, consistency, and potency. These are key considerations and will be required as part of the quality control batch release, in consideration of European Pharmacopeia and World Health Organization (2013) guidelines.

              Efforts have been made worldwide trying to refine these potency tests to reduce the number of animals, and today, a single-species guinea pig study may be conducted (Choi et al., 2018).

              Chan Woong Choi a, Jae Hoon Moon b, Jae Ok Kim a, Si Hyung Yoo a, Hyeon Guk Kim c, Jung-Hwan Kim d, Tae Jun Park a, Sung Soon Kim a, Evaluation of Potency on Diphtheria and Tetanus Toxoid for Adult Vaccines by In Vivo Toxin Neutralization Assay Using National Reference Standards. Osong Public Health Res Perspect 20189(5):278−282

              Virus-like particles (VLPs) are multiprotein structures that mimic the organization and conformation of authentic native viruses, but can potentially yield safer and cheaper vaccine candidates due to the lack of a viral genome. VLPs are a high-priority alternative to traditional vaccine development against infectious pathogens due to their safety, simplicity, and favorable immunological characteristics to induce both humoral and cellular immune responses.

              Attenuation or inactivation is not required, which is particularly important because epitopes are commonly modified by inactivation treatments. Compared to individual proteins or peptides, VLPs present conformational epitopes more similar to the native virus therefore, the immune system response is expected to significantly improve. Using molecular biology methods, it is possible to adapt one or more antigens to these multimeric protein structures for broader and more efficient protection.

              It's interesting to note that VLPs for HPV include antibody responses that exceed those following natural HPV infections.

              In the past few years, nucleic acid-based vaccines (i.e., DNA [as plasmids] and RNA [as messenger RNA (mRNA)] vaccines, have been studied as a new therapeutic modality. They pave the way for safe and efficacious biologics to mimic inoculation with live organism-based vaccines, particularly for stimulation of cell-mediated immunity.

              They have advantages over traditional vaccines in terms of safety, efficacy, and inducing both B and T cell response specificity, but there is a technical challenge associated with DNA and RNA vaccines. Since changes of the encoded protein just alter the sequence of the RNA molecule, leaving its physicochemical characteristics largely unaffected, diverse products can be manufactured using the same established production process without any adjustment, saving time and reducing costs when compared with other vaccine development platforms.


              Tonton video: Beginilah Cara Kerja Vaksin (Oktober 2022).