[Vaccines and adverse events between risk and fear].

The decrease in the incidence of infectious diseases caused by vaccination is responsible for the huge importance given to adverse reactions from both population and health care personnel. Generally no real relationship exists between the true risks associated with vaccines and the risk perceived by the population. This aspect is confirmed by the results of a survey performed in 2009 among 376 students of the University of Roma Tor Vergata and 84 health care workers of the vaccination centers in Lazio Region.