[Evaluation of the immune status against the viruses of measles, mumps, rubella, and hepatitis B in a cohort of students from the province of Como].

Immunity status to measles, mumps, rubella and type B hepatitis (HB) viruses was studied in a cohort of 83 teen-agers (13-14 years). The vaccination against these agents is optional in Italy. Out of 83 subjects none had been vaccinated against measles, mumps and HB viruses, while 31 had had rubella vaccination. The percentage of seronegative adolescents was 2% for measles, 25% for mumps and 10% for rubella among unvaccinated teen-agers. These data suggest that even adolescent could be a target for rubella and mumps vaccination. On the contrary HBV does not appear to circulate extensively in the early years of life, so there is no need to extend the vaccination outside the risk groups. The presence of antibodies to measles, mumps and rubella viruses correlated very well with the anamnestic recall referred by the mothers. On the contrary for rubella and mumps viruses there was a high proportion of seropositive subjects with a negative history of disease. Therefore in the population under study asymptomatic infections with rubella and mumps viruses should have been rather frequent.