Doctors say that with children out of their homes after COVID-19-related lockdowns, common viruses that all disappeared during the pandemic are also re-emerging.
“This time of year in children’s hospitals, it’s usually quiet,” said Dr. Fatima Kakkar, a pediatric infectious disease specialist at CHU Sainte-Justine in Montreal. “But we are now seeing an increase in respiratory infections.”
The level of non-COVID illnesses is what you usually see in the fall, when children are out in nurseries or schools, Kakkar said.
While public health measures taken in the past year — including physical distancing, hiding and staying at home — have been used to stem the spread of COVID-19, they have also had the side benefit of preventing other respiratory viruses, including the common cold and syncytial virus. Respiratory Syndrome (RSV) and human parainfluenza virus, which causes croup.
But experts say that also means that because children haven’t come into contact with those viruses for so long, they haven’t made the antibodies they normally have – and won’t have the immunity they might have otherwise.
“What happened to us is that we … were not exposed,” said Dr. Allison McGeer, an infectious disease specialist and microbiologist at Sinai Health in Toronto.
“Now that we’re back to normal and kids can see each other, we’re starting to see that infection [again] in children.”
Children usually recover from most of these illnesses on their own, but Kakkar said pediatricians are particularly concerned about a rise in RSV. Although it is a common virus, it can cause breathing problems in infants and young children that are severe enough to require hospital care, she said.
Last month, the US Centers for Disease Control and Prevention Issue a health advice Notifying health care providers that RSV cases are on the rise in parts of the country, and requiring them to test children with severe respiratory symptoms for RSV if COVID-19 is ruled out.
According to the CDC, RSV is the most common cause of bronchiolitis and pneumonia in children under one year of age.
The flu is still coming
One of the respiratory viruses that doctors have yet to see is influenza, Kakkar said.
But after a year of essentially no flu season, largely due to COVID-19 precautions, the flu is expected to return this fall.
Doctors say that although our immune systems may not be ready for the flu this year, there is good news.
“People are worried about the flu coming back. But for the flu, we have a safe and effective vaccine,” said Dr. Elaine Foxman, an immunologist at Yale University School of Medicine in New Haven, Connecticut.
“This is a great year to get a flu shot if you haven’t already,” Foxman said, noting that she gets her three children every year.
Although children get more respiratory infections, doctors say parents should not be alarmed.
“This is not a big deal for most kids,” McGuire said.

Additionally, she said, parents can use many of the same precautions they learned during the COVID-19 pandemic to help prevent the spread of childhood viruses that have re-emerged.
“Wash your hands,” McGuire said. “We know that simple things reduce the risk of a respiratory viral infection.”
“[There’s] Good evidence that washing your hands five times a day reduces risk by about 30 percent, whether it does or not.
Kakkar said that staying home when you are sick and keeping your child home if they develop symptoms is also a behavior that has been adopted during COVID-19 and should continue.
In addition, parents should now be prepared to deal with viruses that they usually did not expect until fall.
“Pretend it’s October,” she said.
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