Kids Are Bigger Silent Spreaders Of COVID-19 Than We Realized

Children may be less likely than adults to become severely sick with COVID-19, but mounting evidence shows they may be major silent spreaders of the virus.

A study published this week in the Journal of Pediatrics looked at nearly 200 children who came to urgent care clinics or hospitals associated with Massachusetts General with suspected COVID-19, almost 50 of whom tested positive.

Most of the children were not particularly ill. Only about half who tested positive for had a fever, for example. Many had no symptoms, but had been in contact with someone who had the virus.

Nonetheless, many of the kids had high viral loads in their upper airways, particularly early on in their infections. And, in general, the higher a person’s viral load, the more disease particles they’re likely to exhale when they cough, speak or breathe.

“Intuitively, the more you have, the more you can spread. If you have a million viral particles and you sneeze, compared to somebody who has 1,000, you will spread many more particles,” Dr. Alessio Fasano, director of the Mucosal Immunology and Biology Research Center at Massachusetts General Hospital and an author on the study, told HuffPost.

But that has not been proven.

“Having a high viral load in the nasopharynx (nasal pathways) sounds alarming, but if you think about it from a scientific standpoint, having higher detectable RNA of a virus in the nose may mean that it just stays there in younger children, and not necessarily [that it] spreads down to the lungs, as it might in older teens or adults,” said Dr. Priya Soni, a pediatric infectious disease specialist at Los Angeles’ Cedars-Sinai Medical Center who was not involved in the new study.

Growing research suggests children may contribute to the spread of COVID-19, though they do not necessarily become very sick themselves. 

“We still have a lot to determine about what a higher viral load in the nose pathways really means for clinical disease and for transmission,” added Soni.

She praised the new study as “well structured,” but cautioned against applying the findings too broadly, because — as has been the case with much of the research on COVID-19 — the population of positive patients included was relatively small.

Questions about the role children play in spreading COVID-19 have certainly been intensifying as schools and universities grapple with their plans for the 2021-21 school year. Many schools have opted to be fully remote; others have opened buildings, only to quickly shutter. New York City, the largest U.S. school district, plans a hybrid reopening model in a few weeks.

“We cannot have high-density classrooms. We cannot have children that move from one classroom to another … [and] they all need to wear masks. Not wearing masks would be a disaster, because that’s how this very high viral load could spread very easily.”

– Dr. Alessio Fasano, Massachusetts General Hospital

The researchers behind the new study believe their findings have implications for parents and policymakers. It’s good news that most research continues to show children are generally ― although certainly not always ― less susceptible than adults to severe illness.

But the growing likelihood that even asymptomatic children can carry significant levels of the virus suggests that reopening schools could accelerate community spread of the virus, particularly if schools fail to adhere to public health recommendations.

“As scientists and clinicians, we provide data. What to do with that data is up to policymakers,” said Fasano.

He cautioned that government officials should not be “cavalier” about reopening schools without taking measures to decrease the spread of the virus. Failing to do that, he said, could trigger a “third wave” of infection driven largely by children.

“I’m not saying schools should not reopen … but if they decide to open the schools, they need to follow very strict rules,” Fasano said. “We cannot have high-density classrooms. We cannot have children that move from one classroom to another … [and] they all need to wear masks. Not wearing masks would be a disaster, because that’s how this very high viral load could spread very easily.”

The American Academy of Pediatrics has expanded its guidance about reopening schools, emphasizing that areas with high community spread of COVID-19 make it unsafe to open classrooms.

Where in-person learning is possible, the group calls for masks for all students and staff ages 2 and up; physical distancing in classrooms of at least 3 feet; and co-hosting students to minimize crossover between students and adults.

Experts also emphasized the need for more research in children, and urgent expansion of the country’s coronavirus testing.

“I think the fact remains that we are largely under-testing our pediatric patients,” Soni said. “It’s a vicious circle, because we’re not testing the kids because their symptoms are so mild. … But in not doing so, we lack the large population data on this age group to really make any solid assumptions that can shape policy.”