Via The Globe and Mail: Patchy vaccination rates raise measles outbreak concerns in Ontario as U.S. battles emergency. Excerpt:
Large numbers of children and teenagers in pockets of Ontario haven’t been vaccinated, creating the threat of a measles outbreak similar to the ones health officials are battling in the United States.
This finding comes from a new analysis conducted by researchers at Public Health Ontario. It is the first official estimate of how many children in the province aren’t vaccinated, and provides important clues about who they are and where they live.
“We have pockets where we know we’re not anywhere near where we need to be,” said Noni MacDonald, a vaccine expert based at Dalhousie University in Halifax, who was not involved in the study.
The findings show that the percentage of students in the province with no record of receiving any vaccinations is as much as 2.9. It’s unclear whether all of those students were unvaccinated, or if some were up-to-date with their shots but hadn’t informed the local public-health unit. The study, published last week in the journal Vaccine, looked at children between the ages of 7 and 17, and was based on the 2016-17 school year.
Nearly 1 per cent of the students with no vaccinations on record also had a non-medical exemption on file. Non-medical exemptions for reasons of conscience or religion can be granted to students whose parents object to vaccination in Ontario, where vaccinations are required for school attendance.
Sarah Wilson, a public-health physician at Public Health Toronto and lead author of the study, said it’s reasonable to assume that most or all of those students haven’t been vaccinated.
Those students tended to have things in common. For instance, unvaccinated children with non-medical exemptions were more likely to go to private or religious school, or be home-schooled, live in a rural area or a community with a small- to medium-sized population and be located in the southwest and central west regions.
The numbers of unvaccinated students were much higher in some parts of the province. For instance, in Oxford County, nearly 5 per cent of students were unvaccinated and had a non-medical exemption. In Elgin County, that number was 3 per cent.
Dr. MacDonald said that while the percentages may seem small, they represent tens of thousands of students across the province. “This is not a denominator of 50 kids or 100 kids. This denominator is big … especially when they’re clustered together," she said.
Dr. Wilson said looking at these counties in more detail, such as by school or by neighbourhood, would likely reveal pockets where non-vaccination rates were even higher. And it illustrates why health officials are so concerned about the possibility of an outbreak.
