Quality assessment of DNA vaccines: hepatitis-B vaccine.
Vaccines manufactured following "classical" methods contain inactivated or infectious but attenuated viruses or bacteria. In some instances, the inactivated agents are purified. In other cases, the vaccines contain protein subunits or practically pure polysaccharides. It is generally accepted that the final product cannot be completely characterised and that therefore extensive "in-process" controls are necessary to prove the consistent quality of such vaccines. Control tests are carried out on the substrate, the pooled bulk vaccine and on the final containers. Vaccines produced by recombinant DNA techniques consist of pure proteins. The production is carried out by the multiplication of the "working seed" under well-defined standardised conditions followed by clarification, extraction, purification, formulation. "In-process" controls are incorporated at each step and specifications for acceptance are formulated. The biological methods used for the classical vaccines are completed by physicochemical and immunological determinations of antigen content, identity and purity for the "new generation" products. The requirements for the manufacturers are based on the documents issued by the World Health Organisation and by the national control authorities. The marketing of vaccines is based on a lot by lot release procedure, whereby each lot is tested by the manufacturer and the national control authority before use. Hepatitis-B vaccine, derived from transformed yeast cells, is the first and sole vaccine which has obtained a world-wide license. The quality assessment of this vaccine has been achieved following the requirements for the new generation of biomolecules. It is an example for future vaccines.
Peetermans
J H
JH
Smith Kline-RIT, Rixensart, Belgium.
D000818:Animals; D004274:DNA, Recombinant; D017325:Hepatitis B Vaccines; D006801:Humans; D011786:Quality Control; D014614:Vaccines, Synthetic / Q000138:chemical synthesis* / Q000494:pharmacology; D014761:Viral Hepatitis Vaccines / Q000138:chemical synthesis* / Q000494:pharmacology
D004274:DNA, Recombinant; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines