Elimination of serum proteins and potential virus contaminants during hepatitis B vaccine preparation.

As first generation hepatitis B vaccines are derived from human plasma, detailed information is required concerning the elimination of hepatitis B virus and other potential transmissible infectious agents during vaccine preparation. To demonstrate the safety of a hepatitis B vaccine, the efficiency of each of the six main steps used in the preparation process to remove or destroy pathogens was determined for representatives of major groups of animal viruses. Infectivity of all the tested viruses was reduced 10(5)-fold to a factor of 10(9)-fold by the first and last steps, namely PEG fractionation and formalin treatment.

The use of various immunochemical, biochemical and biological methods for the analysis of rabies virus production in tissue cultures.

For the preparation of rabies vaccines, virus was grown in cultures of primary cells (bovine fetal kidney) or heteroploid cell lines (Hak and Vero). Comparative analysis of concentrated and/or purified antigen has shown a good correlation between the protective capacity (as determined by the NIH test for potency) on one hand, and hemagglutinating titer, optical absorbance at 280 nm and glycoprotein content (evaluated by the Enzyme-Immuno Assay - EIA) on the other. Furthermore, the evaluation of the respective content of glycoprotein and nucleoprotein (EIA) before and after impairment of viral membrane can be done to know if the rabies glycoprotein is anchored in an intact membrane or not (soluble glycoprotein).

[Production of rabies vaccine in animal diploid cells].

Modalities for production of inactivated rabies vaccine derived from diploid hamster cell cultures are reported. The inactivated concentrated virus, purified by zonal centrifugation, is utilised for the preparation of vaccines destinated to carnivores, either in the form of monovalent vaccine or associated with distemper and canine contagious hepatitis vaccines. The inactivated concentrated virus is utilised for the preparation of bovine vaccine.

Zonal centrifuge purification of human rabies vaccine obtained on bovine fetal kidney cells. Biological results.

An inactivated human rabies vaccine prepared on bovine fetal kidney cells is concentrated and purified by zonal centrifugation. The peak of rabies particles is monitored by hemagglutination. Immunogenicity of the purified particles was evaluated by titration of specific antibodies from vaccinated animals.