President Biden said Friday that schools should "probably all be open" this fall "based on science and the CDC."

The president, who appeared on NBC News' "Today" marking his 100th day in office, added that "there’s not overwhelming evidence that there’s much of a transmission among these young people."

The U.S. is trialing COVID-19 vaccines in children, but only the Pfizer-BioNTech two-dose jab is approved for people 16 and older. Moderna's and Johnson & Johnson’s vaccines received emergency use authorization for people 18 and older. Pfizer last month announced that a Phase 3 trial involving its coronavirus vaccine in adolescents 12 to 15 was found to be safe and 100% effective, but it’s not clear when the FDA would act to expand the EUA.

The company is also testing the vaccine in children ages 6 months to 11 years old. Moderna has also begun testing in kids ages 12 to 17 and said they could expect to see approval for this age group by the fall. Dr. Anthony Fauci, the White House’s chief medical adviser, has warned that younger kids likely won’t see a vaccine until 2022, but he also recently said children can return to in-person learning "without necessarily having everyone vaccinated, all the teachers all the students."


"The default should be, and has been for quite a while, that to the best of our ability, we should try to get children back to school as quickly as we can and keep them in schools," Fauci told Fox News’ Neil Cavuto last month.

Earlier this year, the Centers for Disease Control and Prevention (CDC) released an "operational strategy" guide for K-12 schools, which has since been updated to reflect that schools can safely reopen while maintaining 3 feet of space between students as long as there is universal mask use. However, in communities where coronavirus transmission is high, the agency recommends middle school and high school students be at least 6 feet apart "if cohorting is not possible."

"This recommendation is because COVID-19 transmission dynamics are different in older students – that is, they are more likely to be exposed to SARS-CoV-2 and spread it than younger children," the updated guidelines state.

First Lady Jill Biden, who also appeared on "Today" Friday, was asked about the conflict between teachers' unions and districts, and whether she thought it's time for students to return to in-person learning his fall. 

"I think it depends on -- you know, we're following the science and what the CDC says," she responded. "Each district is different, and -- so I think we have to listen to the experts and science, and then the districts have to decide." 


The CDC also recently released updated guidance for fully vaccinated people but still recommends they wear masks and social distance while indoors.