COVID-19 updates: 345 children currently hospitalized with coronavirus in Texas

Moderna has submitted initial data to the U.S. Food and Drug Administration on its vaccine booster, the pharmaceutical company announced Wednesday.

Its booster candidate would be half the dose (50 micrograms) of the original dosing (two shots of 100 micrograms each).

Federal officials have said they hope to begin administering booster shots for many Americans starting on Sept. 20, with the third shot at least eight months after the second.

The FDA has only authorized booster shots of Pfizer's and Moderna's COVID-19 vaccines for people who are immunocompromised. The Centers for Disease Control and Prevention's independent advisory board also recommended booster shots for those with weakened immune systems.

Pfizer is also seeking authorization for a third dose of its COVID-19 vaccine. The FDA announced Wednesday it will hold a public meeting of its independent advisory committee on Sept. 17 to discuss the application.

-ABC News' Eric Strauss

Even with the delta variant, schools are still safe for children if guidelines are followed, CDC Director Rochelle Walensky said Wednesday at a town hall with the National Parent Teacher Association.

For the most part, Walensky said, "there's more disease happening outside of school than there is happening within a school."

Walensky, a mother of three, said she understands why parents are anxious.

But she added, "What we do know is when we implement the guidance for safe schools -- we implement the masking, the ventilation strategies, the cohorting and the screening strategies -- that we can have our kids be safe."

American Academy of Pediatrics President Dr. Lee Beers said at the town hall that it's still a very small percentage of children who get severely sick. The U.S. saw 200,000 cases among kids in the last week with about 2,000 of them hospitalized, Beers said.

-ABC News' Cheyenne Haslett

With nearly 104,000 hospitalized, U.S. hospitalizations are now at the highest point in more than seven months, according to federal data.

Alabama's ICUs remain 100% full while Georgia's ICUs are over 96% full, federal data show.

Nearly 1,000 COVID-19 deaths are now being reported in the U.S. each day, the highest average in more than five months.

-ABC News' Arielle Mitropoulos

Booster shots are beginning in France on Wednesday.

Eligible recipients include people over the age of 65 and people with underlying health conditions. They must be at least six months out
from their second Pfizer or Moderna shot.

Those who received the single-dose J&J vaccine are also eligible to receive an mRNA booster if at least four weeks have passed since they were vaccinated. 

As of Tuesday, 65.6% of France's total population was fully vaccinated.

-ABC News' Ibtissem Guenfoud