Effectiveness of Measles-Mumps-Rubella Vaccine During a Measles Outbreak Associated with a Congregate Migrant Shelter ¡ª Chicago, Illinois, February¨CApril 2024
What to know
Presentation Day/Time: Wednesday, April 23, 2:55–4:00 pm
Presenter: Chelsea Lutz, PhD, MPH, EIS officer assigned to the National Center for Immunization and Respiratory Diseases, Division of Viral Diseases
What did we do?
A measles outbreak associated with a congregate shelter occurred in Chicago, Illinois during February–April 2024. We estimated group-specific attack rates and effectiveness of MMR vaccine during the outbreak to guide future outbreak response strategies in similar settings.
What did we find?
Cases were less likely to be vaccinated compared to non-cases, although breakthrough cases did occur. Effectiveness of one dose of MMR was 69% and effectiveness of two or more doses was 73%.
Why does it matter?
Breakthrough infections in congregate settings where prolonged, intense, or repeated exposures can occur underscore the importance of ensuring residents are fully vaccinated prior to measles introduction.
Public health efforts that prioritize vaccinating persons without ≥2 MMR doses might improve VE in these settings.
Field Photo
EIS officer Chelsea Lutz, PhD, MPH (EIS Class of 2023) enters data during a vaccination clinic at an intake facility during a measles outbreak associated with a shelter in Chicago, Illinois in March 2023.
