A provincial immunization registry would provide real-time data for everyone — not just public schoolchildren
The graph doesn’t look good.
As Ontario continues to struggle with measles outbreaks, the province’s measles vaccination rate, according to Public Health Ontario’s (PHO) public data, appears to have taken a major hit during the pandemic and never recovered.
In 2019-20, 86 per cent of Ontario seven-year-olds were vaccinated for measles. In 2023-24, the most recent data publicly available, just 70 per cent were.
The data is even more striking in the Greater Toronto and Hamilton area. In Hamilton, rates fell from 91 per cent to 48 per cent. In Peel Region, 78 per cent to 36 per cent. Halton: 83 per cent to 25 per cent.
Ontario’s measles vaccination rate appears to have cratered after the pandemic — but the data doesn’t line up with reality, public health officials say. Public Health Ontario
Fortunately for public health officials, the numbers don’t reflect reality.
Medical officers of health say it’s a data reporting issue that stems from the COVID-19 pandemic — a problem the provincial government could fix by creating an immunization registry.
Such a registry would function as a way for any health-care official to upload records of vaccines they administer to a central, digital database that could then be accessed in real time by other officials.
Parents would no longer have to keep track of their kids’ vaccines with the infamous yellow paper card, and report their shots to schools and child care. Adults would no longer have to call their parents to remind them which immunizations they received as kids.
And everyone in the province, not just those in the school system, would be reliably captured by the data.
Public health units would be able to access that information when responding to outbreaks, “so we can have really good data to know who may be at risk in a school or child-care setting or other place,” said Dr. Monica Hau, Peel Region’s acting chief medical officer of health.
“So absolutely, we’re very much in favour of having an immunization registry.”
Health minister sidesteps calls for registry
Under Ontario’s Immunization of School Pupils Act (ISPA), students must get their routine vaccinations or have a valid exemption.
Since health-care providers aren’t required to report vaccines they administer to public health units, those units have to piece together data on their own.
So, every year, public health units look at the immunization status of all students in their area, said Dr. Christine Navarro of Public Health Ontario. They send letters to parents of kids with missing records, asking them to update the unit. They also run catch-up clinics, set up new immigrants with health-care providers, translate documents and review and enter records when they do come in.
“So, as you can guess, this is a very resource-intensive process,” she said.
During the pandemic, ISPA enforcement went out the window as officials and parents scrambled to deal with the public health emergency of a lifetime. It picked back up during the school year that ended last month, meaning thousands of kids who were vaccinated over the past few years haven’t yet been captured in the data.
When ISPA data collection is disrupted, public health essentially starts flying blind. The act also only covers kids in school, meaning data on adults, infants, preschoolers and other high-risk groups is often missed, the Ontario Immunization Advisory Committee, which advises Public Health Ontario on vaccinations, wrote in its 2024 call for a vaccine registry.
Parents often don’t know they have to submit vaccination records for their kids, Navarro said.
“Some parents may think that because their health-care provider has recorded their child’s immunization information in their health record, that that information is provided to the health unit, and by and large, that is not the case,” she said.
Health Minister Sylvia Jones’s office sidestepped questions about whether her government would consider creating a vaccine registry, and whether it has studied the possibility.
Spokesperson Ema Popovic noted the central database where public health units record vaccinations, and the government’s work on a digital ID tool through which Ontarians will be able to access their own records, neither of which act as an immunization registry.
Popovic added that the government has restored the 75/25 split for public health unit funding between the provincial and municipal governments — which the Ford government itself cut in 2019.
Sneak peek at new data promising
Health units expect to have up-to-date measles vaccination data ready by the fall, and they don’t expect to see a major shift.
Hamilton, which has a 48 per cent vaccination rate for seven-year-olds on paper, shared a glimpse at their updated data with The Trillium. In reality, as of June 5, 96 per cent of Hamilton students born in 2017 have had at least one dose of the measles vaccine, and 90 per cent have had two, the city’s associate medical officer of health said.
That’s not to say everything is perfect. Until the data is in, it’s impossible to say exactly how much of the gap in PHO’s data is due to the rise in anti-vaccine attitudes during the pandemic.
The Simcoe Muskoka District Health Unit said it’s seen a slight increase in the number of measles exemptions this school year — between 4-4.5 per cent, compared to its pre-pandemic exemption rate of about 3–3.5 per cent.
Hamilton said its overall exemption rate this year was 3.3 per cent (4.1 per cent for seven-year-olds and 1.8 per cent for 17-year-olds, compared to 2.8 per cent and 2.7 per cent, respectively, in 2018-19).
Peel’s rate has historically been “fairly low,” under three per cent pre-pandemic, Hau said.
“We’re still waiting for that final number for this year, but we don’t anticipate it to be dramatically different,” she said.
Ontario passed a ‘stress test’, but isn’t in the clear
Even before the pandemic, vaccination rates were less than ideal.
Herd immunity for measles (the point at which a population is protected from outbreaks) sets in at around a 95 per cent vaccination rate, according to the World Health Organization.
When COVID-19 emerged, 95 per cent of Ontario 17-year-olds had had their shots, but just 86 per cent of seven-year-olds had. That’s down from 2013-14, when the rates were 97 and 94 per cent, respectively.
“I can’t emphasize social distrust enough,” epidemiologist Colin Furness said, when asked about declining vaccination rates generally.
Vaccination decisions are often based on what everyone else is doing — and in some circles, it’s now becoming normal to be unvaccinated, he said.
Halton Region’s pre-pandemic age-seven measles vaccination rate of 83 per cent is “low,” he noted.
“Since the pandemic, immunization coverage has gone down,” Navarro said. “And that is a combination of a number of things, including missed opportunities,” meaning missed or forgotten shots during the chaos of the pandemic, she said.
Overall, though, medical officers of health aren’t expecting there to be a ticking time bomb of unvaccinated kids.
If the recent outbreaks were a test, Ontario passed, infectious disease specialist Isaac Bogoch said.
“We just had a huge stress test, right? You’ve got the most transmissible virus on the planet. There were cases in the GTA. There were cases all over the province. If our vaccine rates were truly that low, we would have had way more cases — like, way more cases — but we didn’t,” he said.
Navarro noted that outbreaks were largely limited to unvaccinated “pockets” of the province.
“We do have a good wall of protection,” she said.
Curiously, Southwestern Public Health, at the epicentre of Ontario’s measles outbreak, has a decent age-seven vaccination rate, at 88 per cent.
Navarro said the data misses some private schools that “decline to participate” in vaccine data collection.
“So we don’t have data on students in those schools, and that coincides with the pockets of under-immunized communities where we have seen the spread of measles during this outbreak,” she said.
Despite the stress test, Bogoch was quick to point out that not everything is “peachy.”
“Vaccine rates are too low,” he said. “We’re definitely at risk for further outbreaks, and we have to do better to lower barriers to vaccination. We have to have better and stronger and (more) consistent community outreach, and get those vaccine rates high — or higher.”