Lockdowns Kept Children From Acquiring Immunity to Contagious Respiratory Virus: Ontario Pediatrician

Paramedics and ambulances are seen outside the emergency department at Burnaby Hospital in Burnaby, B.C., on May 30, 2022. (Darryl Dyck/The Canadian Press)

With respiratory syncytial virus (RSV) surging coast to coast across Canada, children’s hospitals have been reporting long wait times and overwhelmed emergency rooms due to unprecedented cases of the highly contagious illness, which causes cold-like symptoms in older children but can be very serious in infants.

Children usually accumulate immunity over time to RSV, says Dr. Melissa Langevin, a pediatrician and associate medical director of emergency medicine at the Children’s Hospital of Eastern Ontario (CHEO) in Ottawa, at an Oct. 26 CHEO briefing. Langevin said, however, that the last three years of COVID-19 and lockdowns meant “kids not interacting in the same way.”

“RSV is a virus that normally you probably are in contact with every year or every other year, and so you sort of accumulate an immunity over time. And what we’re seeing is this cohort of kids who have had much less exposure to viruses as would have had in the past years,” she said.

During the first half of November, children’s hospitals across the country reported being in an emergency situation due to RSV admissions. RSV activity, which typically peaks in the winter, is rising and is above expected levels for this time of year, according to Public Health Agency of Canada data.

Some 1,309 cases were detected among 16,856 tests conducted for the week ending Nov. 5. This is a test positivity rate of 7.77 percent, more than double the rate of 3.57 percent from three weeks earlier, for the week ending Oct. 15, when just over 500 cases were detected out of 14,114 tests.

‘Immunity Gap’

According to a commentary published July 14 in The Lancet medical journal, the predictable seasonal circulation patterns of many endemic viral illnesses in children changed due to non-pharmaceutical interventions (NPIs) and societal behavioural changes during the COVID-19 pandemic, and these viruses are now resurging in unexpected ways.

“Decreased exposure to endemic viruses created an immunity gap—a group of susceptible individuals who avoided infection and therefore lack pathogen-specific immunity to protect against future infection,” wrote the authors, who include Dr. Kevin Messacar, associate professor of pediatrics at Children’s Hospital Colorado in Denver, and Rachel Baker, assistant professor of epidemiology at Brown University in Providence, Rhode Island.

“We knew it was inevitable that these diseases would come back,” Messacar said, reported CNN in an article dated Oct. 28. “The degree of societal changes that occurred with the COVID pandemic really is unprecedented in modern day.”

Changes in NPIs or societal behaviours—such as ongoing mask-wearing, working from home, and social distancing—leading to even moderate alterations in viral transmission rates “could greatly impact the magnitude of future outbreaks” in children, the Lancet study said.

A May 2021 study published in the journal Infectious Diseases Now said the lack of immune stimulation induced an “immunity debt,” suggesting that once various NPIs are lifted, and the “longer these periods of ‘viral or bacterial low-exposure’ are due to COVID lockdowns, the greater the likelihood of future epidemics.”

“This is due to a growing proportion of ’susceptible' people and a declined herd immunity in the population,” the study said.

RSV Season Came Early

A CHEO spokesperson told The Epoch Times that the hospital is in an emergency situation due to RSV and is operating with “all hands on deck.”

President and CEO Alex Munter said at the briefing that in the last week of October, the hospital had 10 times the average number of admissions for RSV than it had pre-pandemic. Peak viral season came early, driven by acute viral respiratory infections, at levels never before seen in the hospital’s 48-year history.

Munter said that by the end of October, pediatric medical units at CHEO were at 134 percent of occupancy, with pediatric intensive care at 124 percent. On Nov. 9, CHEO announced it had opened a second pediatric intensive care unit to address the overflow of critically ill babies and young children, as it deals with more than double its normal volume of younger patients.

Joining Munter and Langevin to discuss the reasons RSV is on the rise this year were Dr. Chuck Hui, chief of infectious disease, immunology, and allergy, and pediatrician Dr. Anne Pham-Huy.

Hui said CHEO’s experience with RSV admissions reflects what’s happening across the rest of Ontario as well as south of the border in the United States.

“We’re seeing a significant number and an increased number of RSV cases, and also a significant increase in RSV hospitalizations. And this is an early surge,” he said.

Langevin said children under age 2 or 3 are going to be more susceptible to symptoms and that “RSV tends to be more severe if you’re exposed to a higher viral load.” She said it’s possible kids are being exposed to multiple people with a higher viral load and slightly more severe symptoms.

“It’s like the perfect storm,” Pham-Huy said, as “you have the combination of both a larger susceptible cohort of kids, in combination with behavioral stuff, to back to school and circulation of all the mix of viruses at the same time.”

“RSV is here earlier than it usually is,” she added, “and so we’re seeing the cases and the surges.”

A similar situation was found Nov. 9 at the emergency departments of the London Health Sciences Centre in London, Ontario. The hospital issued a press release stating that wait times could be 20-plus hours for non-emergency concerns.

RSV can take a week or two to resolve, and symptoms include coughing, fever, runny nose, and a loss of appetite and energy, says the Canadian Paediatric Society. In more severe cases, hospitalization is required where supplementary oxygen or intravenous fluids can be given if needed. Babies are most at risk of serious complications.

Each year, RSV disease is estimated to cause 3.4 million hospitalizations and 100,000 deaths globally, with peak infections during the winter months.

Ontario Medical Association president Dr. Rose Zacharias told CTV on Nov. 10, “This is the first year since the pandemic began that we’re heading into a normal flu season.”

“We are definitely feeling that wave,” said Langevin. “What’s important to know is that this is something we know well. RSV is part of our regular bread and butter.”