You might know that young kids don’t experience symptoms of COVID as often as teenagers and adults – but now a recent study that Henry Ford Health participated in has found a likely reason as to why.
Participants who carried the COVID virus in their nose but had a rhinovirus infection (the common cold) within the past 30 days were 48% less likely to get sick.
“This study showed that when you get COVID, your immune system turns on 25 antiviral pathways to fight the disease,” says Christine Johnson, Ph.D., a research scientist at Henry Ford Health. “It turns out that 22 of these antiviral pathways were also turned on to fight rhinovirus. So if you’ve recently had a cold, your immune system is already primed to fight COVID so well that it doesn’t become an established infection and you don’t get sick.
“Little kids carry rhinovirus a lot – there are many types of rhinoviruses. So that’s why we think they don’t get symptomatic COVID infections as often. In some ways, it’s like being vaccinated, which revs up your immune system to fight a virus more rapidly, but this works even more quickly.”
Kids Get COVID More Often Than Adults But Are Less Likely To Get Sick
Henry Ford Health was one of 12 sites – the only in Michigan – that participated in this study, which was funded by the National Institute of Allergy and Infectious Disease (NIAID).
From May 2020 – February 2021, at-home COVID testing kits were distributed to participating families every two weeks, along with when anyone in the family had a respiratory disease. The kits included nasal swabs to measure the viral load in their noses, along with a simple self-collected blood-drawing device and stool sample collectors. Each family mailed their specimens to a designated lab.
Previous findings from this study discovered that children younger than 13 had COVID in their nose more often but were asymptomatic 75% of the time. When teenagers and adults had the virus in their nose, they developed symptoms more than 60% of the time.
“How sick you get from COVID depends upon your viral load,” says Dr. Johnson. “When a child had COVID, their viral load was low because they were fighting off the virus so quickly. When adults had COVID, the viral load in their nose was much higher.”
Scientists are still analyzing the data they compiled from this study to continue learning as much as possible about COVID. As for this latest discovery, Dr. Johnson says knowing rhinovirus shares immune response properties with COVID could help us be better prepared if a similar disease circulates in the future.
Reviewed by Christine Johnson, Ph.D., M.P.H., Chair of the Department of Public Health Sciences at Henry Ford Health.
