US vaccination rates have been falling as the supply has increased - CNN

In the meantime, Slavitt said: "Not only do we want to get it done in time for school, we want to get it done in time so that kids can really enjoy their summer activities without having to worry, without having to wear their masks."

Fauci asks young people to 'be part of the solution'

When the FDA does authorize a vaccine for them, Fauci said he hopes children and teens won't hesitate.

"You have the capability of protecting yourself as a young person, 12 to 15, but also knowing that you're not going to pass it on to someone else," Fauci said.

"You even want to call upon the young people to say, 'I want to protect myself, but I want to be part of the solution, not part of the problem.'"

Adding millions more people to the vaccinated population would make a big difference in terms of building up population immunity, Dr.

Ashish Jha, dean of the Brown University School of Health, told CNN.

Pfizer and Moderna are testing their vaccines in children as young as 6 months old and expect to ask the FDA for EUAs covering infants and children later this year.

States set dates to reopen

The US may not be at herd immunity levels yet, but states are preparing for major easing of restrictions.

On Thursday, Los Angeles and San Francisco will advance into California's least restrictive reopening tier, allowing most businesses to resume indoor operations.

Both areas, which account for about a quarter of the state's population, have case rates lower than 2 per 100,000 residents.