Measles vaccine rates may be warning sign in COVID fight

Low numbers in some schools raise concerns about vaccine hesitancy Some health units failing to keep accurate records on immunization

A mass immunization campaign to beat COVID-19 will likely require the vaccination of school kids. In Ontario, that could be a problem.

A Star analysis of immunization data for 1.5 million students enrolled in nearly 4,400 Ontario schools reveals that in some school districts there are concerning gaps in vaccinations for measles, one of the world’s most highly infectious diseases. At more than 200 Ontario schools, records show less than 80 per cent of students are up to date with their measles, mumps and rubella (MMR) vaccinations, well below the threshold of 95 per cent required to achieve herd immunity and prevent outbreaks.

The problem is particularly bad in Halton, where at seven elementary schools, fewer than half of all students have a record of being vaccinated.

The World Health Organization (WHO) unit overseeing the COVID-19 response views measles vaccination rates as a key indicator of a country’s ability to respond to a crisis and the accuracy of vaccination records as a barometer of how well a public health system is operating.

Ontario’s data, and its blind spots, is a clear sign that the government “needs to get its act together,” said Dr. Natasha Crowcroft, a former leader at Public

Health Ontario who is now based in Geneva, Switzerland, as a senior technical adviser on measles and rubella control with the WHO.

The immunization data, collected directly from Ontario’s public health units, offers a snapshot of vaccination rates at the time the units collected the information, which ranged from July 1, 2019, to Nov. 1, 2019. Rates may have since changed.

Across the province, roughly 33,000 students formally opted out of taking the vaccine for philosophical or religious reasons, health units’ data show. And it is not known whether tens of thousands more are vaccinated because some public health units have failed to keep accurate, up-to-date records as required by Ontario’s Immunization of Student Pupils Act.

“If public health units are not putting resources into measles immunization programs, that’s a massive oversight,” said Crowcroft. “If your data is bad, your coverage is bad until proven otherwise. I would be worried if I were in any of the health units that has a major gap.”

As Ontario begins easing pandemic restrictions and people resume congregating, Crowcroft and other public health experts warn the risk of measles outbreaks is real.

Some researchers are also exploring a connection between measles vaccinations and COVID-19 outcomes. Studies around the world are suggesting that people who have received two doses of the MMR vaccine may have less severe reactions to COVID-19 infections.

While there is still debate around the role schools and children play in the community spread of COVID-19 as kids often display mild systems or no sign of infection, there is a strong argument that vaccinating children will be required in a successful national immunization campaign.

“If we want to reach the 60 to 80 per cent coverage needed to stop transmission of the virus, we’re going to have to vaccinate kids,” said Dr. Peter Hotez, a renowned expert in infectious diseases and vaccine development at Baylor College of Medicine in Houston, Texas. Hotez is part of a team working on a COVID-19 vaccine for children that is being scaled for production in India.

Trials are underway for COVID-19 vaccines that can be safely used in children, with hopes they may be ready as soon as spring.

If and when a COVID-19 immunization rollout begins for Canadian children, public health experts worry the rising number of families objecting to safe, proven childhood vaccinations for highly infectious diseases like measles will also decline jabs to protect against the novel coronavirus, which has been the subject of conspiracy theories and political divide.

“These are the parent groups that are going to refuse to take the COVID-19 vaccine, I’m sure,” Hotez said. “It could be a huge problem, no question about it.”

Children with exemptions have a greater risk of acquiring and transmitting vaccine-preventable diseases. Measles outbreaks typically occur in schools with more unvaccinated children, and unvaccinated children are 35 times more likely to contract measles as their vaccinated peers, studies have shown.

Southwestern Public Health has one of the highest rates of exemptions in the province with 11 per cent of 1,772 students in the town of Aylmer opting out of the MMR vaccine for philosophical or religious reasons.

“We emphasize that those who can be vaccinated should be vaccinated to protect the few who are medically exempt,” said Dr. Joyce Lock, Southwestern’s medical officer of health. Changing minds, she said, will take time and trust.

“Much of our work in the realms of health promotion, health protection and disease prevention is incremental and the relationships required to see wide-scale community health change take months or even years to develop. This is true of immunization.”

In the data released by Ontario’s public health units, vaccination records are missing for more than 78,000 students.

An estimated 5,000 of those students have medical exemptions, which most of the health units did not track in the records they shared.

Whether the remaining 73,000 students’ missing records relate to vaccine-hesitant families or barriers to health care are questions public health units need to figure out. And fast.

“That’s quite worrying,” said Crowcroft, who has kept one remote foot in Ontario as an adjunct professor at University of Toronto’s Centre for Vaccine Preventable Diseases. “We don’t know where these parents fall. We’ll find out when the COVID vaccine is available for younger age groups.”

Forty-two Ontario schools show MMR vaccination rates below 60 per cent. Nearly 90 per cent of these schools are in Halton, while the others are located in Toronto, Niagara and York. These pockets could provide an entry point for measles outbreaks.

“Measles doesn’t care about COVID,” Crowcroft said. “It’s just going to carry on regardless. We can’t afford to create one problem while we’re solving another.”

Four of 34 public health units refused requests to provide school-level vaccination data: Chatham-Kent, HaldimandNorfolk, North Bay-Parry Sound and Thunder Bay.

In Halton, which includes the municipalities of Burlington, Halton Hills, Milton and Oakville, nearly one in four public and Catholic school students — more than 23,000 kids — had no record of mumps, measles and rubella immunization as of July 1, 2019.

Provincial legislation requires every public health unit to collect and store accurate and upto-date immunization information on every student in their jurisdiction.

Halton Public Health said its MMR coverage rates “should be considered to be severe underestimates of the true coverage in each school” because immunization is self-reported, so students with no record of immunization may in fact have been vaccinated.

Halton Public Health said the region’s coverage rates may be driven down by the fact its data includes students as young as four, whereas other health units’ cover students ages seven to 17. The second MMR dose can be administered any time between the ages of four and six.

“Including young children is expected to decrease the Halton rates compared to Toronto; however it captures the whole school population starting in junior kindergarten,” the public health unit said in a statement.

Halton Public Health also noted that unlike most units, its data includes children who are “due” for vaccination rather than only those who are “overdue,” which may inflate the region’s rates.

Like every public health unit in Ontario, Halton’s relies on parents to submit their children’s vaccination records. The unit’s job is to make sure that happens, and when it doesn’t, issue suspension letters to students. Halton has long had a spotty record of enforcement.

The unit told the Star it ordered schools to enforce suspensions for just five groups of students based on birth year and grade. The unit cited resource issues for failing to monitor students from all birth years and grades more regularly.

And the health unit is falling further behind. Halton stopped reviewing and updating student files last spring when it redirected staff to its COVID-19 efforts.

The pandemic would have had no impact on the vaccination rates shown in the Star’s report, which were collected between July and November 2019 — before the novel coronavirus arrived in Canada.

Halton’s health unit said it has refocused its resources to provide hepatitis B, HPV and meningococcal vaccinations — typically administered in school in Grade 7 — through community-based clinics to students who missed the shots.

Halton could not provide updated school-based data on MMR vaccinations, but said its records show the number of seven- and eight-year-old students with proof of immunization or exemption for all school-related vaccines rose to 80 per cent in 2019-20 from 36 per cent a year earlier.

Ontario knows the system isn’t working. The Health Ministry had piloted a new live data entry program so vaccination records could be logged at the point of the prick, but that system was shelved in 2018 when physicians reported it was incompatible with their office software.

The government had planned to amend legislation to require doctors and other health-care providers to report children’s vaccinations, but those efforts “remain paused at this time,” a government spokesperson said.

“This is very concerning,” Halton District School Board chair Andréa Grebenc told the Star.

She said she thinks it’s important for parents to know what immunization rates are at their child’s school for the health of the whole family.

“Maybe we have a greater (vaccine) hesitancy in our region, I don’t know,” Grebenc said. Since the pandemic began, Grebenc said she’s “received personally as a trustee letters and emails from people begging me to do something to make sure we aren’t going to be vaccinated because we’re all going to become robot zombies.

“I blame the government for not working really hard on that hesitancy. It’s been hitting us for years with vaccinations obviously if we have some schools with only 39 per cent of students known to be vaccinated.

“And here we are going to be offering a vaccine for the current pandemic and they’re going to be bumping up against the same thing.”

One of the lowest MMR vaccine coverage rates in the province was found at École Élémentaire du Chêne in Oakville, part of Halton’s health unit within the CS Viamonde School Board. In 2019, records show 39.8 per cent of students were up to date.

Julie Vanghelder, a CS Viamonde spokesperson, told the Star that the board is ultimately just a messenger for the public health unit, which is responsible for making sure students are either vaccinated or formally exempt. She said the “immunization process has been on hold” since the start of the pandemic.

Vanghelder said CS Viamonde schools cut across 13 different health units, some of which have begun collecting completed JK registration immuniza- tion forms and pickups. Others are planning to resume the vac- cine program in catch-up clin- ics at various high schools and community sites.

Toronto Public Health said it was unable to provide any school-based vaccinations, including the MMR vaccine, for the 2020-21 school year because its staff has been focused on the pandemic response.

“We know that high vaccination rates in schools and in the community are important to prevent the spread of highly contagious viruses such as measles,” said Toronto’s associate medical officer of health, Dr. Vinita Dubey. “As travel restrictions are relaxed and more people interact while in close contact, importation of measles into Toronto will be likely, as has been the situation in previous years.”

Measles is spread through droplets from the nose, mouth or throat of infected persons.

Blindness, brain swelling, severe diarrhea and related dehydration, and pneumonia are among the most serious complications.

Measles surged worldwide to nearly 870,000 cases in 2019, reaching its highest number of reported cases in 23 years. Global measles deaths climbed nearly 50 per cent since 2016, killing an estimated 207,500 in 2019 alone. Health Canada reported 113 cases of measles in 2019, compared to 29 cases in 2018.

Canadian health officials reported just a single case in 2020 with most schools shuttered and many parts of the country under lockdown for months.

Doctors cite a failure to vaccinate children on time with two doses of vaccine at ages 12 to 15 months and four to six years as the main driver of increases in measles cases and deaths.

The importance of a two-dose MMR vaccination may be more crucial than ever, with new research suggesting it may protect against COVID-19.

Nearly a dozen studies published in 2020 have drawn a link between childhood vaccination and COVID-19.

“While travel restrictions, control of congregate living conditions and governmental interventions play roles in controlling the COVID-19 spread, it is possible that MMR vaccination programs are the basis for the huge international variation,” wrote Dr. J. Wesson Ashford of Stanford University in the American Journal of Medicine.

“Double childhood MMR vaccination can generate antibodies lasting for 20 or more years,” he writes. “Long-term benefit declines with age ... This pattern is consistent with the observed progressive increase of COVID-19 infection and death rates up to 45 years of age.”

In the journal mBio, researchers at several academic institutions across the United States compared MMR antibodies in 50 COVID -19 patients to the severity of their symptoms. Those with high levels of mumps antibodies from MMR vaccinations had mild or no symptoms of COVID-19. Subjects with moderate and severe cases of COVID-19 all had low levels of mumps antibodies.

Additional research notes the measles vaccine increases the immune system’s ability to fight non-measles pathogens, including coronaviruses. Researchers are also investigating the benefits of two other common childhood vaccinations — jabs protecting against tuberculosis and hepatitis A — to keep COVID-19 at bay.

In September, Moderna, one of the two companies approved to produce a COVID-19 vaccine for adults in Canada, announced it was starting the second of its three-phase study in American adolescents ages 12 to 17.

The other vaccine approved so far for the Canadian market is from Pfizer and the German company BioNTech. Its clinical trial for children 12 to 15 is fully enrolled.