What We Know Now about Children’s COVID-19 Risks in Schools

The leader of a teacher’s union, an infectious disease pediatrician, and an academic researcher discussed whether it’s possible for children to safely return to school, during a webcast hosted by the Association of Health Care Journalists on Thursday.

Their answer, of course, is it depends.

It depends on whether the rate of infection in the community is low enough, whether schools have enacted protocols that could mitigate the spread of the virus, and on individual student characteristics.

“One thing to remember is that anyone can be infected with COVID-19,” said Tina Q. Tan, MD, professor of pediatrics and a pediatric infectious diseases physician at Northwestern University’s Feinberg School of Medicine in Chicago.

That may sound obvious, but as recently as Thursday evening, President Trump insisted that young people are “almost immune” to COVID-19.

Children do tend to have lower rates of infection, said Tan, and have either mild symptoms — with cough and fever being the most common — or none at all.

Yet, it is possible for even asymptomatic children to infect another person.

That said, research has shown that children under 10 are “less effective transmitters of the COVID-19 virus and infrequently serve as the index case in COVID-19 family clusters or in community spread,” Tan noted.

Does Age Matter?

Current data suggests that the risk among “younger school children” of spreading the virus to teachers has been “low” especially when mitigation protocols are implemented, precautions are followed, and transmission in the community is low, Tan said. (Children under age 1 and those with underlying conditions are an exception to this finding.)

Children 10 and older, however are just as likely as any adult to spread the virus in their household or in the community. The reasons for this difference in transmission are not well understood.

It may be that children mount a less intense immune response, that they have more “viral interference” in the respiratory tract (meaning, the SARS CoV-2 virus is competing with other viruses in children’s respiratory tracts leading to a lower viral load), or that there are differences in the expression of the angiotensin-converting enzyme (ACE)2 receptor that COVID-19 binds to in the respiratory tract, Tan said.

All three factors appear to reduce the amounts of infection seen in children.

As children get older, modeling data seems to suggest that they are more capable of a more intense immune response, show less viral interference, and see more ACE2 receptor expression — all of which increases the amount and severity of COVID-19, she said.

Speaking more broadly, Tan also noted that international studies tracking the spread of COVID-19 in schools found low rates of transmission as long as the community transmission itself is low.

“And that’s the key,” Tan said. “You really have to know what your community transmission levels are.”

Responding to New Research

New research, though, called some of these age distinctions into question.

A study published Friday in Morbidity and Mortality Weekly Report suggested that, when exposed, children are as vulnerable to infection as anyone else. Those ages 6-10 at a Georgia summer camp were actually the most likely to test positive for the virus among those 21 or younger, with an “attack rate” of 51%. Rates were 44% among those ages 11-17 and 33% for ages 18-21; for staff, mostly young adults, the rate was 56%.

And a research letter published Thursday in JAMA Pediatrics found that kids’ noses carry greater amounts of the virus than adults.

MedPage Today asked Tan in a phone call whether these new findings have changed her views of transmission and infection among children.

But Tan said her perspective remains unchanged. Again she stressed the significance of community infection levels as critical to any analysis.

In the Georgia study, there was already “a lot of disease in the community” and kids went to camp where, as the article notes, none of the broadly recommended mitigation procedures were implemented, and then there was an outbreak.

Campers weren’t required to wear cloth masks, only staff were; doors weren’t opened to increase ventilation; and campers were housed with 15 children to a cabin. There was no mention of whether beds were appropriately spaced, she said.

Campers also engaged in “vigorous singing” and “cheerleading,” which increase the risk of spreading the virus through small droplets, Tan noted.

“We know that if you practice physical distancing, if everybody wears a mask, if you do what you’re supposed to do, you really decrease the spread and transmission of COVID,” Tan said.

In real-world studies of outbreaks reported in other countries, “it’s not the kids that are transmitting to the teachers; it’s the teachers transmitting to the kids,” she added.

When there’s already a lot of disease in the community and people are traveling from all corners of it to the camp, “there’s an increased risk of exposure” and “an increased risk of transmission of the virus.”

Regarding the higher rates of infection among younger children at the camp, Tan said more young children may have tested positive for the virus, but the study did not say how many children were symptomatic (information on symptoms was available for 136 of the 260 infected individuals; 100 developed symptoms.)

Those who are symptomatic are probably more likely to effectively transmit the virus than those without symptoms, she added.

Tan also pointed out that the nasal carriage study did not show that children were as effective as adults in transmitting the virus. Detecting viral RNA does not equate to finding infectious virus particles, she said.

No Easy Answers

For parents asking the question of whether their kids should return to school, Tan recommended focusing on a few core factors in addition to the level of community infection: asking whether schools have adapted “mitigation protocols,” and considering ways their children learn best.

If the level of infection in the community is high — meaning a test positivity rate of 5% or higher — “it would not be a good idea for schools to reopen or for parents to send their children to school at that time,” Tan said.

If community infection rates are low, the types of mitigation protocols that could help minimize the risk of spread would include physically distancing, wearing face coverings, practicing good hand hygiene, cleaning and disinfecting frequently touched surfaces, conducting symptom screening, and having a plan for what to do if a student or teacher tests positive.

“All of these measures really need to be in place prior to a school opening to … foster a safe school environment,” Tan said.

There are clear advantages of classroom learning that cannot be replicated through distance learning, she acknowledged, including the development of language, communication, and interpersonal skills.

Schools also help narrow racial and social inequities, but a virtual-only learning curriculum actually increases the risk of worsening such disparities in access to high-quality education, Tan said.

Enriqueta Bond, PhD, chair of the National Academies of Sciences, Engineering, and Medicine (NASEM) Committee on Guidance for K-12 Education on Responding to COVID-19, in weighing the health benefits and risks against the educational risks and benefits around school reopenings, ultimately helped issue a report on July 15 encouraging reopening, particularly for students in kindergarten through fifth grade.

NASEM also recommended prioritizing physical distancing, limiting large gatherings, and creating small cohorts of students.

“We felt very very strongly that districts should provide surgical masks for all teachers and staff as well as supplies for effective hand hygiene,” Bond said.

She emphasized the need for strong partnerships between public health officials and school officials to develop mitigation protocols and plans for tracking data on the virus, as well as to develop COVID-19 prevention training and inform decision-making.

The decision on whether to reopen will ultimately be local, “and it might have to be made over and over again,” Bond said.

‘A Bake Sale Can’t Fix This Problem’

Lily Eskelsen García, president of the National Education Association hesitated to recommend that children return to the classroom for in-person teaching.

“Nobody wants those kids back more than their teachers,” except perhaps their parents, she said. But “[t]here shouldn’t be anything that says that we have to sacrifice their health and safety.”

In none of the countries that President Trump cited as examples of successful reopenings were they forced to ask: “How do you go back to school when it’s not safe?”

“Nobody asked that question. They did it in a safe way,” Eskelsen García said, because their political leaders took the virus seriously from the start.

“We’re not going to open up schools until it’s safe,” she stated firmly.

In addition to verifying that community infection rates are low — below 5% — schools must develop plans appropriate for their community, and they must have the resources to keep staff and students protected.

Eskelsen García shared the story of a teacher who started a GoFundMe page to buy face masks when she learned the district didn’t have the money. Proud of her own idea, the teacher encouraged Eskelsen García to share the suggestion with other teachers.

“I’m not going to share that idea with all of our teachers. This is not about a bake sale,” she said.

Another school secretary bought disinfectant supplies for the school after she learned the district woudn’t provide the money for them. Eskelsen García said she herself is accustomed to schools running low on items like tissues, soap, and toilet paper halfway through the year.

Something people may not recognize is that one of the greatest sources of funding in public schools is the wallets of teachers and staff, Eskelsen García said. “So, we have no faith that politicians are going to give us what we need to do this safely, and we’re worried about that.”

(See also MedPage Today’s What Evidence is Aiding School Reopening Decisions?)