[Post-licensing surveillance of vaccines]

Pharmacoepidemiological studies are essential in the post-licensing surveillance of vaccines in order to evaluate the potential benefits and risks of vaccines used in common practice. Surveillance is required to detect rare or unanticipated vaccine adverse events and to ensure confidence in vaccination. Epidemiological studies provide data on the long-term protection conferred by vaccination, and the incidence and associated mortality of, and population susceptibility to, diseases preventable by vaccine. These studies also allow verification of the compatibility between strains contained in the vaccine as well as circulating strains.