WASHINGTON - Advisors to the US Food and Drug Administration (FDA) are set for a key meeting Tuesday on whether to recommend the Pfizer-BioNTech COVID-19 vaccine for children ages 5 to 11, as experts predicted younger kids will be eligible for the vaccine in early November.

The FDA's Vaccines and Related Biological Products Advisory Committee is scheduled to meet on Tuesday to discuss whether to approve the vaccine. If authorized, it would be the first COVID-19 vaccine for younger children.

Anthony Fauci, the nation's top infectious disease expert, said some 28 million children ages 5 to 11 in the United States may be able to receive their COVID-19 vaccine in the first two weeks of November.

"You never want to get ahead of the FDA in their regulatory decisions, nor do you want to get ahead of the CDC and their advisers on what the recommended would be," Fauci said in an interview with ABC News.

"But if you look at the data that's been made public and announced by the company, the data looked good as to the efficacy and the safety," he said.

Pfizer and its partner BioNTech said their COVID-19 vaccine is safe and 90.7 percent effective against symptomatic COVID-19 in children ages 5 to 11, according to a document posted on the FDA website ahead of the meeting.

Pfizer and BioNTech are applying FDA emergency use authorization (EUA) of a two-dose regimen of 10-microgram dose for children ages 5 to 11, which would be administered three weeks apart.

The most common side effects occurred after the second dose and included pain at the injection site, fatigue and headache.

There were no serious adverse events associated with the vaccine, according to the FDA.

Moderna also announced Monday that a study in children ages 6 to 11 found two doses of its COVID-19 vaccine given 28 days apart produced a strong antibody response.

The Phase 2/3 study, called the KidCOVE study, gave over 4,700 participants two 50 microgram doses of the Moderna COVID-19 vaccine mRNA-1273, half the dose authorized for adults.

The interim analysis showed a "robust neutralizing antibody response" after two doses given 28 days apart, according to Moderna.

The most common side effects were fatigue, headache, fever and pain at the site of injection. Moderna said the analysis showed a "favorable safety profile."

Nearly 6.3 million children have tested positive for COVID-19 since the onset of the pandemic, according to latest data updated by the American Academy of Pediatrics (AAP) on Monday.

Almost 118,000 child COVID-19 cases were added over the past week. Over 1 million child cases were added over the past six weeks, according to the AAP.

Although weekly cases decreased from the peak of nearly 252,000 child cases on the week of Sept 2, a total of 118,000 cases remains an "extremely high number" of newly diagnosed children, said the AAP.

Health experts stressed to get children eligible for COVID-19 vaccine as soon as possible is key to curb the increase in child cases, and prevent the virus from spreading to other vulnerable groups.