Low Rates of Immunity among Medical Students and Residents in the Era of the Resurgence of Measles

Abstract

Measles is a highly contagious viral disease spread through respiratory droplets. The number of reported cases increased worldwide in 2023, particularly in the European Region. Italy reported 213 cases in the first quarter of 2024, with most of them in unvaccinated adults aged 15–64. Maintaining high vaccination coverage is essential to prevent outbreaks, especially in healthcare settings where measles transmission is a significant risk. In our study, we collected serological and demographic information from all Italian and foreign medical students and residents (850) who underwent a pre-training assessment at the Tor Vergata Occupational Medicine Service, Rome, between 3 April 2023 and 31 January 2024. Of the 850 students and residents analyzed, we found only 546 (64.2%) with a protective level of IgG antibodies against measles, with a median IgG level of 2.00 AI. A significant proportion of students and residents were serologically non-immune, raising concerns about the potential risk of hospital transmission. To manage this risk, it is important to assess serological levels, vaccinate those with inadequate levels, and promote vaccination in the general population.