[Epidemiologic situation of rubella in Italy 20 years after the introduction of the vaccine].

Rubella vaccination has been introduced in USA in 1969: it was addressed to all the newborn and to women in childbearing age. In 1970 it was offered in Europe to schoolgirls aged 11-14 and to women of reproductive age. The purposes were identical--namely to eliminate the incidence of CRS--in spite of the different strategies adopted: in fact the American vaccination programme tried to reach this aim in eradicating the disease, while in Europe special attention was given to the possibility of reduce morbidity in childbearing age. After 20 years we can try to verify if these objects have been attained. Recent data (MMWR, 1987) show that rubella morbidity in USA has dropped considerably (incidence rate in 1966 = 24.3; in 1986 = 0.2) and incidence rate for CRS decreased accordingly from 0.90 (1969) to 0.32. Nevertheless we must underline that 47.5% of cases in USA from 1984 to 1986 were seen in person older than 20, and serologic studies have shown that infection susceptibility, in the postpuberal population, is the same that in prevaccinal era (10-20%). Many evaluation of efficacy of vaccinal strategies have been carried out in Europe, always showing a smaller number of women of reproductive age susceptible toward infection, together with a reduced probability of exposure during pregnancy. In European countries, were rubella vaccination has been offered only to women, morbidity has not changed appreciably. In Italy rubella vaccination has not been introduced at the same time and with the same extension in all regions: for this reason it is not possible to evaluate efficacy of this vaccination policy on a whole. Considering ISTAT data from 1971 to 1987 we can identify epidemic outbreaks in 1973, 1978, 1982 (of limited intensity) and 1984; practically every six years, as they took place before vaccination era; if we take into account case notified between 1971 and 1981 in the different age groups (table 1) we can see that the higher prevalence is always in the 6-13 years age group. Vaccination has not modified the epidemiologic trend of the disease. However, considering only the class toward whom vaccination was addressed from the beginning, that is women of reproductive age, that can have had the possibility to be vaccinated in prepuberal years at school or in another occasion, after serologic screening, in adult life, we can notice substantial differences in infection susceptibility in comparison with prevaccinal era, that was about 10-20% (Galli, 1982).(ABSTRACT TRUNCATED AT 400 WORDS)