Donald Trump says students don’t catch, spread COVID-19. Studies say it’s not that simple

As thousands of communities wrestle with reopening their schools this fall, President Donald Trump said he would be comfortable sending his son or a grandchild back to school. Pressed on whether he understood why some districts would see that as too risky, Trump had reassuring words about COVID-19 and students.

"A lot of people are saying they don’t transmit, and we’re looking at that," Trump said in  a July 22 briefing."They don’t catch it easily; they don’t bring it home easily. And if they do catch it, they get better fast. We’re looking at that fact. That is a factor, and we’re looking at that very strongly. We’ll be reporting about that over the next week."

The main problem with Trump’s summary is that it makes no distinction between the youngest and oldest students. Studies are limited. What information we do have from other countries indicates that high schoolers are more like adults, while elementary children present a lower risk. But how those findings might apply in U.S. states with rising case numbers is uncertain.

At one point in the briefing, Trump said, "We have great statistics on young people and on safety."

The record does not support that level of confidence in the data.

Over the past few months, researchers in other countries have broadly divided students by age and found that the older ones are more likely than the younger ones to be infected. 

A recent study out of South Korea looked at more than 1,200 cases of people with COVID-19. It found that the rate of infection was three times higher for children 10 to 19 years old than for children under 10.

In France, about 660 people from one community agreed to be tested for antibodies for the disease. Again, the rate for older children was higher than for younger ones. About 40% of 15- to 17-year-olds tested positive, compared with less than 3% for those under 14.

Epidemiologists in China looked at clusters in Wuhan and Shanghai and tested for the presence of the virus. They used only three age brackets — 14 and under, 15 to 64 and over 64. The youngest group was about a third as likely to have the disease as the adults were. The oldest group had the highest risk.

Those age ranges might not be as helpful as school superintendents would like — 15 to 64 is hardly school-age specific. But the data do show a lower risk for children.

In its guidelines for schools, the Centers for Disease Control and Prevention said infection seems to vary by age, with students 10 to 17 being more likely to catch the disease than those under 10.

For now, U.S. health officials have discussed a lack of data on children and COVID-19 transmission. 

"We don't really know exactly what the efficiency of spread is, first of all, how many children get infected," Dr. Anthony Fauci, the nation’s leading infectious-disease specialist, said at a Senate hearing June 30.

The CDC said more research is needed on school-age children passing the virus on to members of their households. A National Institutes of Health study intends to follow 2,000 families for six months to determine in part how often children get infected and then infect their families.

Our look at existing research on whether children transmit COVID-19 found a complicated picture. 

A July commentary published in the journal of the American Academy of Pediatrics reviewed several studies out of Switzerland, China, France and Australia. Co-author Arnaud L’Huillier told PolitiFact that children can emit live viruses, so there is no biological reason why they couldn’t be contagious. 

But in line with the other research, co-author William Raszka distinguished between younger and older students.

"Children much less frequently transmit SARS-CoV-2 than adults, and this is most striking in younger children," Raszka said. "I worry more about high school students."

Trump’s words lumped all students together, but the emerging message from the research is that age matters, both for catching and spreading the virus. Where the dividing line falls remains unclear. And even for the youngest children, however rare, the virus can be deadly.

Editor's note: This story was updated shortly after publishing to include information from new guidelines for school reopenings released by the CDC.