b型嗜血性桿菌結合疫苗的免疫性與檢驗分析   全文下載

Immunity and Control Analysis of H. Influenzae Type b Polysaccharide-protein Conjugate Vaccine

在美國以及世界各地，b型嗜血性桿菌（HIb）感染是產生細菌性腦膜炎最主要的病因。此菌並且引起肺炎、骨髓炎、細菌血病，會厭炎與膿毒性關節炎等疾病。許多生存者會導致聽力缺陷，智力減退之永久性後遺症。莢膜性多糖類（PRP）為該菌所具有的主要致病毒素，而PRP多糖類抗體為產生血清殺菌作用的重要因素。PRP是胸腺細胞非依存性抗原，不需要T助理細胞之作用就可刺激B細胞的免疫反應。將PRP多糖類與蛋白質，以化學作用結合時可將多糖類抗原之胸腺細胞非依存性變成依存性，而增加免疫反應。現在有三種HIb蛋白質結合疫苗，利用不同的方法製造；即使用不同的蛋白質媒體，多糖類分子大小，化學結合，以及蛋白質與多糖類的比例：（1）Connaught藥廠將白喉變性毒素結合到HIb多糖類；（2）Praxis藥廠將變異的白喉毒素，CRM197，結合到分子較小的HIb多糖類；（3）MSD藥廠則使用40KD腦膜炎外表細胞膜蛋白質，以特殊的化學反應結合到HIb多糖類。Praxis和MSD藥廠製備的結合疫苗對2～6個月以上的嬰孩產生免疫反應。Connanght藥廠研製的疫苗對18個月以上的嬰孩可產生免疫抗體，所有的結合疫苗皆不產生顯著的副作用。HIb結合疫苗的管制檢驗可分為二階段：（A）各批的多糖類要檢驗（1）化學成份，例如ribose，與磷含量；（2）細胞摻雜物質，例如蛋白質，LPS與核酸。蛋白質媒體要檢查其純度，以及LPS，核酸之摻雜物，熱原物質試驗。濃縮半製品要檢驗游離的ribose含量，多糖類與蛋白質之比例，分子大小，以及LPS之摻雜，熱原物質試驗。（B）最終疫苗含有10～15μgPRP劑量。此製品要檢查鑑定分析，HIb糖類的含量測定，游離ribose，游離蛋白質的含量，LPS之摻雜，以及無菌試驗，一般安全性試驗與熱原物質試驗。HIb結合之疫苗的接種對於幼小兒童可防禦HIb的感染疾病。應用同樣的接種策略與化學合成技術，將可防禦由其他莢膜性病原菌所引起的疾病。 "

Haemophilus influenzae type b (HIb) is the widest known cause of bacterial meningitis and a leading cause of bacterial diseases in the United States and many areas of the world. It causes; epiglottitis, pneumonia, septic arthritis, osteomylitis and penricarditis. Many sunvivors of meningitis experience in permanent mild hearing loss and mental retardation. The capsular polysaccharide of polyribosylribitol phosphate (PRP) is a major virulence factor of the organism. Antibody to PRP is the primary contributor to induce serum bactericidal activity. Three types of HIb-protein conjugate vaccines were prepared by different methods, using a different protein carrier, PS size, nature of linkage, and ratio of protein and PS: (1) The Connaught Laboratories combined diphtheria toxoid (DT) to HIb PS by cyanogen bromide activation of PS and conjugation of PS and DT by carbodiimide; (2) In the praxis Biologics, HIb oligosaceharides were conjugated to a mutant diphtheria toxin, CRM197, by the reductive amination; (3) The Merck, Sharp & Dohme conjugate vaccine utilized a 40 KD meningococcal outer membrane protein (OMP) and a mutiple synthetic procedure. HIb PS-protein conjugate vaccine produced high antibody levels in infants 2-6 months of age and young children with no major adverse reactions. Control tests of HIb conjugate vaccine were carried out in two stages: (A) Each lot of PS shall be examined for (1) the chemical content, such as ribose and phosphorus; (2) contamination of cell components, such as protein, LPS and nucleic acids. The carrier protein was then examined for its purity. The conjugate bulk concentrate was next examined for free ribose content, ratio of PS and protein, molecular size, contamination of LPS and pyrogenicity. (B) The final conjugate vaccine contains 10-25 µg PRP per dose. The vaccine was tested for identity and amount of HIb PS, contents of free ribose, free protein, LPS, as well as sterility, general safety and pyrogenicity. Immunization of HIb PS-protein conjugate vaccine holds great promise for the prevention of HIb diseases in young children. An approach using similar technology can be applied to the prevention in the future of diseases caused by other encapsulated bacteria.