Bacterial vaccines safety tests

The single-component bacterial vaccines are listed in Table 15.1. For each vaccine, notes are provided of the basic material fkm which the vaccine is made, the salient production processes and tests for potency and for safety. The multicomponent vaccines that are made by blending together two or more of the single component vaccines are required to meet the potency and safety requirements for each of the single components that they contain. The best known of the combined bacterial vaccines is the adsorbed diphtheria, tetanus and pertussis vaccine (DTPerWac/Ads) that is used to immunize infants, and the adsorbed diphtheria and tetanus vaccine (DTWac/Ads) that is used to reinforce the immunity of school entrants. 

Viral vaccines present problems of safety testing far more complex than those experienced with bacterial vaccines. With killed viral vaccines the potential hazards are those due to incomplete virus inactivation and the consequent presence of residual live virus in the preparation. The tests used to detect such live virus consist of the inoculation of susceptible tissue cultures and of susceptible animals. The cultures are examined for cytopathic effects and the animals for symptoms of disease and histological evidence of infection at autopsy. This test is of particular importance in inactivated poliomyelitis vaccine, the vaccine being injected intraspinally into monkeys. At autopsy, sections of brain and spinal cord are examined microscopically for the histological lesions indicative of proliferating poliovirus. 

This vaccine was tested for safety and immunogenicity in 24 human subjects. The injection elicited local moderate pain with no other notable physiologic abnormalities found. The vaccine increased antibody levels up to 12 months after the initial vaccination. Using functional tests such as activation of white cells ex vivo, cytokine generation, and bacterial clearance, the authors found a higher capacity for neutralizing bacteria and activating white cells (Cross et al., 2003). 

Viral vaccines can present problems of safety testing far more complex than those experienced with most bacterial vaccines. With killed viral vac-... 

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