Investigation of a measles outbreak in a highly vaccinated middle school, France, 2023.

ABSTRACT: In September 2023, a measles outbreak occurred in a middle school (Rhône valley, France), with the index case returning from Asia. Investigations involved case validation, virological analyses, contact tracing and checking vaccination records to determine measles vaccination coverage (VC) and attack rates (AR). Among 643 students, 49 measles cases occurred between 6 September and 18 October 2023 (AR = 7.6%). Two-dose vaccination coverage was 93.5% (601/643). Virological analyses confirmed the measles strains' clonality (genotype D8) and the imported origin. Concordance between health record vaccination status and immunological profile was established for 27 cases. In a sub-cohort of children (all cases and 309 non-cases), AR was 100% in unvaccinated children, and 43.7%, 16.5% and 3.2% amon

SUBMITTER: Benet T 

PROVIDER: S-EPMC12639275 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature