Dr. Scott Gottlieb on Friday warned against comparing the risks of the coronavirus for children with those from the seasonal influenza, stressing that much remains unknown about Covid-19. 

“The reality is that flu last year infected 11.8 million kids. We have not infected anywhere near that number of kids with Covid, and we don’t want to find out what it might look like if we did,” Gottlieb said on “Closing Bell.”

The U.S. has nearly 4.1 million confirmed cases of Covid-19, according to a Johns Hopkins University tally. 

Gottlieb’s comments come as school districts across the U.S. prepare plans for fall classes amid the nation’s ongoing coronavirus epidemic. The Trump administration has in recent weeks been intensifying its calls for schools to fully reopen for in-person class. In early July, President Donald Trump threatened to withhold federal funding to those that do not open. 

And on Thursday, the U.S. Centers for Disease Control and Prevention released updated guidelines for school districts, placing a heavy emphasis on the social and emotional costs of not reopening for in-person class. The CDC guidelines said the best available evidence indicates children have a lower risk of contracting the disease than adults.

As of data from mid-July, people under the age of 18 make up less than 7% of confirmed cases and under .1% of deaths related to Covid-19, according to the CDC.

But Gottlieb said the CDC guidelines also “rather grimly” compare the number of deaths in children from Covid-19 to the number of deaths in children caused by seasonal flu. “So far in this pandemic, deaths of children are less than in each of the last five flu seasons, with only 64,” the CDC guidelines state. 

That is true, said Gottlieb, the former Food and Drug Administration commissioner under Trump. ”The actual incidence of hospitalizations and deaths thankfully is low” for children with coronavirus, Gottlieb said. “But the reality is that most kids probably haven’t been infected with Covid.” 

For that reason, he said, “we really do want to prevent outbreaks in the school setting.” 

Gottlieb has consistently emphasized he believes it is possible for schools to safely reopen for in-person class during the pandemic. But he also has sought to paint the decision as a localized one that requires consideration of the region’s Covid-19 outbreak.

“It’s going to be very hard for communities to open schools for in-class learning against the backdrop of really epidemic, uncontrolled spread,” he said. “The good news is a lot of parts of the country the epidemic is under some semblance of control. … I think those states are going to have the opportunity to try to open their schools in the fall, at least for a period of time.” 

Disclosure: Scott Gottlieb is a CNBC contributor and a member of the boards of Pfizer, genetic-testing start-up Tempus and biotech company Illumina.