Seroepidemiological evaluation of 1989-91 mass vaccination campaigns against measles, in Italy

In 1989-91 anti-measles vaccination campaigns were conducted in several Ita lian regions to vaccinate all children aged between 13 months and 10-12 yea rs without a history of measles or measles vaccination. This study was cond ucted to evaluate serological status after the mass vaccination campaigns. In 1994, capillary blood samples were collected from randomly selected chil dren, aged 2-14 years, living in 13 local health units. Antibody titres wer e determined by ELISA. Blood spot samples were analysed for 4114 (75.6 %) o f 5440 selected children. Among the 835 that reported measles before 1990, 806 (96.5 %) were immune and of the 2798 vaccinated, 2665 (95.2 %) were imm une. The Edmoston-Zagreb (E-Z) strain vaccine was associated with a lower l evel of immunity than the Schwarz (SW) strain. A history of measles identif ied almost all immune children. Vaccination with the SW strain conferred pe rsistent immunity (at least 5 years) in 98 % of vaccinees. The strategy was able to unite natural and induced immunity.