The Ontario Ministry of Health has expanded eligibility criteria for the measles vaccine in Grey-Bruce, in response to increased exposure risk in western Ontario.
Ontario’s Chief Medical Officer of Health urged families to seek earlier measles vaccinations for infants and young children as the region continues to see new cases of the highly contagious airborne virus.
The move comes as the region records 40 confirmed or probable cases since a multi-jurisdictional measles outbreak began in October 2024. Thirty-two of those cases have been reported this year, with nearly all involving unvaccinated individuals.
Under the revised guidelines:
Infants aged 6 to 11 months are now advised to receive one dose of the measles, mumps, rubella (MMR) vaccine. These children will still require two additional doses after turning one.
Children aged 1 to 4 years who have received one dose should get their second dose as soon as possible, at least four weeks after the first.
Adults born in 1970 or later are encouraged to ensure they’ve received two doses of a measles-containing vaccine.
While the risk to fully immunized individuals remains low, health officials warn that measles spreads rapidly among those who are not vaccinated or immune. One dose of the vaccine offers 85 per cent to 95 per cent protection, while two doses raise efficacy to nearly 100 per cent.
Grey Bruce Public Health has launched a dedicated measles information webpage with vaccination details, exposure locations, and virus facts.
Health officials continue to stress the importance of immunization in protecting individuals and communities against preventable diseases like measles.