Prevalence of measles virus-specific IgG antibodies according to vaccination schedule in medical students of Padua University

Abstract

Aims: The goal of the present study was to establish the efficacy of the measles vaccine and the validity of the vaccination schedule adopted in Italy. Materials & methods: The following procedures are adopted: analyze the compliance to the vaccination schedule; assess the seroprevalence of measles antibodies according to the year of birth and the number of doses; and investigate the persistence of positive antibodies post-vaccination. We gathered and elaborated data of both vaccination history and seroprevalence against measles in a large population of students (4195) belonging to the Medical School of Padua University (Italy). Results: Our results reveal a requirement for a two-dose vaccination schedule to ensure protection from the disease. Nevertheless, these results clearly indicate that the percentage of seropositivity reached using the two-dose strategy is below the percentage (95%) that ensures optimal population immunity. Conclusion: It is uncertain whether immune coverage persists when circulating antibodies vanish, but two vaccine doses should prevent disease outbreaks.