RISKS ASSOCIATED WITH VACCINATIONS

Since Jenner and Pasteur, various vaccines have been developed and adm inistered in immunization program conducted by WHO in order to diminis h the circulation of pathogenic agents and eradicate some diseases. Ri sks associated with immunization are revealed by the collection and as sessment of adverse events reported after the use of these drugs. They vary according to the type of vaccines. With high rates of immunizati on and a low incidence of infectious diseases, adverse events receive increasing attention. Frequent and mostly expected adverse events are reported in clinical trials. Unexpected rare adverse events are report ed after marketing authorization by spontaneous reporting and post mar keting surveillance studies. Post marketing surveillance should be ada pted to vaccines (vaccino-vigilance) and should take into account the risk linked to the disease they may protect against. Adverse events ar e often temporally associated with vaccines, that does not mean they a re causally related. Specific studies should be conducted to ar;sess t he causal relationship between vaccines and post immunization adverse events. In order to reduce the risk associated with immunization, a st rict follow-up of recommendations, warnings and contraindications in a ddition to appropriate information being delivered to both vaccinees a nd physicians are required.