Measles vaccine virus mutation following vaccination in a healthy child resulting in a false negative vaccine specific PCR test: Ontario, Canada, 2025
Paediatrics
Measles vaccine virus mutation following vaccination in a healthy child resulting in a false negative vaccine specific PCR test: Ontario, Canada, 2025
Paediatrics

Measles vaccine virus mutation following vaccination in a healthy child resulting in a false negative vaccine specific PCR test: Ontario, Canada, 2025

Euro Surveill. 2025 Oct;30(43). doi: 10.2807/1560-7917.ES.2025.30.43.2500774.

ABSTRACT

We report a case of a mild, self-limited rash illness in a child 18 days after measles-mumps-rubella-varicella vaccination. Initial testing with a PCR-based method failed to detect vaccine virus. Sequencing later identified a novel mutation in the probe-binding site of the vaccine assay that had arisen after vaccination and resulted in the false-negative PCR test results.

PMID:41170572 | DOI:10.2807/1560-7917.ES.2025.30.43.2500774