Children and teenagers account for about one in five COVID-19 cases across Canada since the start of the pandemic, and some experts anticipate that figure could rise during the fourth wave as millions of unvaccinated children return to school.

Among those ages 12 to 17, about 74 per cent have received at least one dose of a COVID-19 vaccine, and 53 per cent are fully vaccinated, according to the latest government data. No COVID-19 vaccine is yet approved for children under 12, but in Ontario the Pfizer vaccine is now available for those who will turn 12 this year.

We asked experts how they anticipate COVID-19 will affect children this fall.

HOW WILL A FOURTH WAVE COMPARE WITH PREVIOUS WAVES OF THE PANDEMIC?

While the first COVID-19 wave hit older adults hardest, and subsequent waves have sickened increasingly younger age groups, the fourth wave will likely disproportionately affect children and others who are not fully vaccinated, said Nazeem Muhajarine, a professor of community health and epidemiology at the University of Saskatchewan.

Currently, children and teenagers, from newborns to 19-year-olds, make up 19 per cent of COVID-19 cases across the country, tied with those ages 20 to 29 for the largest share of cases, the latest government data show.

In provinces that have lifted public-health measures such as mandatory mask-wearing, the Delta variant will likely spread very quickly through schools and child-care settings this fall, as unvaccinated students spend long periods of time together indoors, said Tehseen Ladha, assistant professor in the department of pediatrics at the University of Alberta.

The Delta variant, which is nearly twice as contagious as the original SARS-CoV-2 virus, “is a totally different ballgame,” Dr. Ladha said. “We’re looking at a scenario where even the risk-mitigation strategies that may have worked before, like cloth masks in small crowded classrooms of kids, may not be effective enough.”

In the worst-case scenario with few public-health measures, some experts say, millions of children could be infected.

“Just in Alberta alone, there’s over 500,000 that are under 12 and we anticipate that many will get infected come fall if they’re in school or child care,” Dr. Ladha said. “And so when you look at the scale of Canada, it would be millions.”

SINCE MOST CHILDREN EXPERIENCE ONLY ASYMPTOMATIC OR MILD COVID-19, HOW MUCH DO CASE COUNTS MATTER?

Most experts anticipate SARS-CoV-2 will likely never disappear completely, and continue to circulate in Canada and elsewhere. But they disagree on when to shift the attention away from asymptomatic and mild cases to focus only on severe COVID-19 cases and deaths.

“We will not eliminate COVID, which means we need to learn how to live with it,” Alberta’s Chief Medical Officer of Health, Deena Hinshaw, wrote in a statement earlier this month, explaining her province’s plan to move away from widespread testing and from requiring those with symptoms to isolate. The province has since delayed lifting these measures until Sept. 27.

Meanwhile, Ontario’s Chief Medical Officer of Health, Kieran Moore, told a news conference earlier this month he believed the province needs “to normalize COVID-19 for the schools” by adopting an approach that’s cautious yet recognizes the likelihood that cases will rise.

Some say it’s not yet time to stop tracking new infections. Even though Canada’s relatively high vaccination rate means most of the population will be protected from hospitalizations and deaths, daily tallies of new cases are an important indictor of whether there’s an upswing in infections, said Dr. Muhajarine, who is also a member of the federally funded research group Coronavirus Variants Rapid Response Network.

Keeping those daily new case counts low should remain a priority, he said. Mutations of the coronavirus are constantly occurring, some of which can make it more transmissible and deadly. To prevent a more threatening version of the virus from taking hold, it’s important to suppress the spread of new infections, he said.

“We want to nip it right at the bud,” he said. “If there’s no new cases, that also means that we are driving the virus to the ground.”

WHAT DO SURGING PEDIATRIC CASES AND HOSPITALIZATIONS IN THE U.S. SAY ABOUT WHAT WILL HAPPEN IN CANADA?

In the U.S., COVID-19 cases among children have climbed steadily since July, and have increased by more than 215,000 cases, or 5 per cent, in the two-week period ending Aug. 12, according to the American Academy of Pediatrics. Amid that rise, hospitals in Texas, Florida and Louisiana have been hammered by a surge of pediatric COVID-19 patients.

While pediatricians in Canada are eyeing the U.S. situation closely, it’s hard to say whether Canada will see a similar trend, said Jesse Papenburg, a pediatric infectious diseases physician at Montreal Children’s Hospital.

Dr. Papenburg said he has yet to see detailed U.S. data showing the ages of pediatric hospital patients and the rates of vaccination among eligible children ages 12 and older in areas of the southern states where hospitals have been hardest hit. In those areas, it may be possible that additional regional factors, such as weather and humidity, may be contributing to COVID-19 transmission, he said.

HOW DOES THE DELTA VARIANT AFFECT CHILDREN?

Even though newborns to 19-year-olds now make up a large proportion of cases, they still account for a small share of hospitalizations, intensive care admissions and deaths. Since the start of the pandemic, this age group has accounted for 1.9 per cent of hospitalizations, 1.2 per cent of intensive care admissions and 0.1 per cent of deaths in Canada, according to government data.

However, the number of children who get seriously ill and require hospital care will inevitably increase as more children become infected, Dr. Ladha said.

The numbers of children who experience the rare but serious multisystem inflammatory syndrome (MIS-C), which generally affects children after a COVID-19 infection, and “long COVID,” estimated to affect anywhere from 3 per cent to 12 per cent, are also expected to rise, Dr. Ladha said. Individuals with “long COVID” continue to experience symptoms, such as shortness of breath, pain, fatigue and cognitive problems, months after infection.

While research shows the Delta variant is more transmissible than the original SARS-CoV-2 virus, it’s still unclear whether it causes more severe disease, Dr. Papenburg said. Some data in adults suggest it may but it’s even more unclear whether this is the case in children, he said.

WHAT WILL AN INCREASE IN PEDIATRIC COVID-19 CASES MEAN FOR THE HEALTH CARE SYSTEM?

Even a small increase in pediatric hospitalizations could overwhelm the health care system, Dr. Ladha said.

“Pediatric ICUs operate at maximum capacity. They’re generally 100-per-cent full. There aren’t an abundance of pediatric intensive care physicians, nurses, respiratory therapists,” Dr. Ladha said.

This doesn’t just apply to intensive care, but to pediatric critical care, in general, Dr. Papenburg added, noting hospitals aren’t limited so much by the number of beds as they are by specially trained staff.

Since Canada’s pediatric intensive care units are concentrated in large urban centres, young patients experiencing respiratory failure in more remote areas may need urgent air transportation, he said.

“From a medical perspective, it is a challenge and can be suboptimal for patient care to have to fly them out,” he said. “It’s a huge burden on the medical system, on the patients themselves and on the families of patients that come from these underserviced communities.”

WHEN CAN CANADA EXPECT VACCINES TO BECOME AVAILABLE FOR CHILDREN UNDER 12?

The first vaccine trials were conducted in adults, and subsequent trials have been testing the vaccine in younger age groups.

Earlier this month, Moderna’s chief executive officer Stéphane Bancel said he expects his company will be able to submit data on its vaccine for children, ages 6 to 11, for Canadian regulatory approval by early fall, and for children, ages six months to five years, by end of 2021.

Dr. Papenburg, who is a member of the National Advisory Committee on Immunization (NACI), said the committee is expecting Pfizer to provide data in October on its vaccine for those ages 5 to 11.

The Pfizer/BioNTech vaccine is currently the only one approved in Canada for those ages 12 and older. (Ontario announced this week all children turning 12 this year are now eligible to receive it.)

Although the AstraZeneca and Johnson and Johnson vaccines are approved for use in adults by Health Canada, provinces stopped offering the AstraZeneca product as a first dose this spring amid reports of a rare blood-clotting issue, and no doses of the Johnson and Johnson product have been given in the country, owing to safety concern at a U.S. plant where an ingredient in Canada’s first shipment of the vaccine was made.

Dr. Ladha said any rise in illness and hospitalizations among children is “unacceptable” since they are preventable with vaccines. That’s why measures are needed in the interim, she said, such as installing high-efficiency particulate air (HEPA) filter units in every classroom and making sure children have high-quality masks.

“This really behooves us to be thinking about putting into place other protective measures for children so that we’re not almost intentionally infecting them,” she said.

She recommends KN95 respirators or snug-fitting, multilayered cloth masks, preferably with a metal nosepiece, adjustable ear loops and made with three layers of material, including a middle layer of polypropylene. Surgical masks tend not to fit the face well enough and leave gaps on the sides, Dr. Ladha said.

WHAT CAN FAMILIES DO TO KEEP THEIR CHILDREN SAFE FROM COVID-19?

“It’s a little bit out of parents’ hands because the provinces have their back-to-school plans and the schools, to a large degree, have to follow these,” Dr. Papenburg said.

He noted, however, that wearing masks has been shown to help decrease COVID-19 transmission in schools.

Because of the increased transmissibility of the Delta variant, an estimated 90 per cent of the total population will need to be fully vaccinated to significantly slow its spread, Dr. Papenburg said.

In the meantime, individuals who are fully vaccinated will have to continue to act as though they’re still vulnerable, Dr. Muhajarine said. That includes wearing masks in indoor public places, and keeping at a distance from people whose vaccine status is unknown.

WHAT DO THE PROVINCES’ BACK-TO-SCHOOL PLANS LOOK LIKE?

B.C. is expected to provide an update on its back-to-school plan later this month, which will include whether or not masking will be required. The union representing public school teachers has called for a mask mandate.

Alberta’s back-to-school plan does not require masks, but says they may be recommended during outbreaks, and allows schools to choose to make additional mask requirements. Edmonton Public Schools back-to-school plan is stricter in so far as requiring all staff and students to wear masks. The Calgary Board of Education is also requiring masks indoors for all staff and students, from kindergarten to Grade 12. As part of the province’s plan, students and staff must screen daily for symptoms and isolate if they have symptoms or test positive for COVID-19. Cohorting and maintaining physical distance is not required.

Saskatchewan has said schools will go back to operating as they did before the pandemic, with no requirements for masks, physical distancing or other COVID-19 restrictions. On its website, the Saskatchewan Teachers’ Federation said this approach could change throughout the school year by region, and school divisions can decide which health measures to retain. Earlier this week, the teachers’ federation called on the government to make vaccines mandatory for all eligible students and staff.

Manitoba’s plan recommends masks, but does not make them mandatory.

In Ontario, families have a choice between in-person or remote learning, and early figures from boards show that most are opting to send their children back into the bricks-and-mortar classrooms. Students in Grades 1 to 12 will be required to wear masks and maintain physical distance indoors wherever possible. They must also undergo daily health checks. Schools without mechanical ventilation systems are expected to have a HEPA filter unit in every classroom. Earlier this week, the Toronto District School Board, Canada’s largest school board, released its back-to-school guidance that follows similar rules as last year, where elementary students will eat lunch in their classrooms and remain with their cohorts when outside for recess. Assemblies will not be held, unless they are virtual, singing indoors will be allowed as long as kids are masked, and all students, including those in kindergarten, will be required to wear masks indoors.

Quebec requires masks in common areas, but not in classrooms, and does not have physical distancing guidelines for students. That province says it is also taking measures to monitor and improve air quality in schools.

New Brunswick, Nova Scotia and Prince Edward Island have yet to release their back-to-school plans.

If low case counts continue in Newfoundland and Labrador, schools there will begin the academic year in a “low-risk” designation, which means cohorts and distancing are not required. Masks are encouraged, but not required, and in-person gatherings and events can resume for Grades 7 to 12, but virtual options should be considered for younger grades. A “high-risk” designation would mean prioritizing virtual gatherings, and likely a return of masks, cohorting and physical distance measures. The province says this could require a temporary shift to blended or online learning.

In Yukon, students do not need to wear masks in class, but those ages five years and older, and staff must wear them in all indoor settings beyond the classroom. Physical distancing is no longer mandatory, but staff must stay two metres away from students and each other, or wear a mask when that is not possible.

Schools in the Northwest Territories will return to normal, with a few exceptions. There will be no performance programs, including drama, choir and band, no large gatherings and assemblies, and no high-contact physical activities indoors, such as wrestling. While masks will not be required in class, they will be mandatory on school buses and within the school buildings outside of the classroom.

In Nunavut, school operations will depend on the status of COVID-19 in each community; the health care capacity of a community; and the public-health capacity to test, trace and isolate cases, as well as vaccine coverage, according to the Department of Education. Mask requirements are left up to Nunavut’s Chief Public Health Officer, but even when these requirements are not necessary, the territory’s Department of Education requires visitors who are not fully vaccinated to wear masks in school.

WENCY LEUNG
HEALTH REPORTER
The Globe and Mail, August 18, 2021