Ontario's first measles death in decades offers grim reminder that unvaccinated kids are at risk

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An Ontario child's death from measles this year offers a grim reminder: When vaccination rates drop and this virus rears its head, the youngest among us bear the brunt.

Public Health Ontario (PHO) reported the recent death of a child under five on Thursday. The child, from Hamilton, Ont., was one of five unvaccinated kids who fell ill and ended up in hospital this year, with 22 cases of measles in total reported so far across the province.

That means, in mere months in 2024, Ontario has hit nearly a quarter of the roughly 100 measles cases documented in the entire decade beforehand. And PHO said this year's death marks the province's first deadly case since 1989 — as far back as its data goes.

Renowned infectious diseases specialist Dr. Allison McGeer called it a tragedy, but not a surprise.

"It's something that people have spent a lot of time and effort to try to avoid," added McGeer, who works at Sinai Health System in Toronto. "There's also a certain aspect of inevitability to it just because of how much ground we lost in measles vaccination around the world."

Globally, and in Canada, immunization rates against various infectious diseases have backslid in recent years. That's given measles — once thought of as a disease of the past — a chance to come roaring back. 

In Ontario, for instance, the proportion of seven-year-olds who had zero vaccine doses rose dramatically, from less than four to nearly 17 per cent, between the 2019-2020 season and 2022-2023, a March PHO report noted.

"Many people might have missed a dose of a vaccine during the darker days of the pandemic when several public health programs were curtailed because of the enormous impact that COVID was having," said Dr. Isaac Bogoch, an infectious diseases specialist with the University Health Network.

It's a similar scene elsewhere. Measles cases spiked this year in Montreal and other parts of Quebec; infections in the U.S. have already hit their highest level since 2019; and outbreaks keep appearing globally, including an ongoing cluster of cases in London, U.K.

People travelling to and from hot spots also means this virus is now routinely hopping around the globe, as PHO noted in its latest report, with 15 of the province's recent cases directly tied to travel abroad.

It's also highly contagious: Measles can linger in the air for hours, and one infected person can spread it to nine out of 10 unprotected people around them. 

Most at risk? Children who aren't yet vaccinated, multiple medical experts stressed.

"If you look at the data from any of the provinces," McGeer said, "it's unvaccinated kids who are the problem."