originally Published: 15 JUN 22 15:14 ET

Updated: 15 JUN 22 15:18 ET

By Jacqueline Howard, CNN

(CNN) -- Vaccine advisers to the US Food and Drug Administration voted unanimously on Wednesday in favor of expanding the emergency use authorization for the Moderna Covid-19 vaccine to include younger children.

All 21 members of the FDA's Vaccines and Related Biological Products Advisory Committee voted "yes" in response to the question: Based on the totality of scientific evidence available, do the benefits of the Moderna COVID-19 Vaccine when administered as a 2-dose series (25 micrograms each dose) outweigh its risks for use in infants and children 6 months through 5 years of age?

The committee is expected to vote later Wednesday on whether it supports authorization of Pfizer's Covid-19 vaccine for children younger than 5.

Children younger than 5 are the only age group not currently eligible to be vaccinated against Covid-19. About 17 million kids under the age of 5 will become eligible for Covid-19 vaccines once they're authorized for this age group.

The FDA, which typically follows the committee's decisions, will now decide whether to authorize the vaccine for emergency use in this young age group.

However, shots can't be given until the US Centers for Disease Control and Prevention's own vaccine advisers have voted on whether to recommend them and CDC Director Dr. Rochelle Walensky has signed off on the recommendation.

CDC's vaccine advisers are expected to vote on Saturday. The White House has said shots could begin as early as next week.

'Benefits seem to clearly outweigh the risks'

"The benefits seem to clearly outweigh the risks, particularly for those with young children who may be in kindergarten or in collective childcare," said committee member Oveta Fuller, an associate professor of microbiology and immunology at the University of Michigan Medical School, said of the Moderna vaccine.

VRBPAC member Dr. Art Reingold added that even though the risk of Covid-19 hospitalization and death is lower for young children than adults, children tend to receive vaccinations to protect them against diseases for which their risk is low.

"If we have a vaccine with benefits that outweigh the risks, then making it available to people is a reasonable choice," said Reingold, of the University of California, Berkeley.

"I would point out that we as a country continue to give a large number of vaccines to children where the risk of the child dying or being hospitalized of those diseases are pretty close to zero," Reingold said, referring to diseases such as polio and measles.

The number of Covid-19 hospitalizations and deaths in children is concerning and much higher when compared with influenza-related deaths and hospitalizations, FDA official Dr. Peter Marks said in Wednesday's meeting, before the committee voted.

"There still was during the Omicron wave a relatively high rate of hospitalization during this period," Marks, director of the FDA's Center for Biologics Evaluation and Research, said. "That rate of hospitalization actually is quite troubling and if we compare this to what we see in a terrible influenza season, it is worse."

Marks said the number of deaths for children ages 4 and under during the first two years of the pandemic "also compares quite terribly to what we've seen with influenza in the past."

"We are dealing with an issue where I think we have to be careful that we don't become numb to the number of pediatric deaths because of the overwhelming number of older deaths here. Every life is important," he said, adding that "vaccine-preventable deaths are ones we would like to try to do something about."

Marks said the Covid-19 vaccines are an intervention similar to the influenza vaccine, which has been broadly and routinely used and accepted to prevent deaths.

The Moderna vaccine is already authorized for adults. In a previous meeting Tuesday, VRBPAC members unanimously voted in favor of expanding the emergency use authorization of Moderna's vaccine to include older children and teens, ages 6 to 17, saying it would offer more benefits than risks.

Covid-19 vaccine 'well-tolerated' in youngest children

Moderna's Covid-19 vaccine, when administered as a 25-microgram dose, is "well-tolerated" in children ages 6 months to 5, Dr. Rituparna Das, Moderna's vice president of Covid-19 vaccines clinical development, told VRBPAC members Wednesday, as she described the safety profile of the vaccine among this age group and adverse reactions.

"Pain was the most common event," Das said. "Young children's events included fever, headache, fatigue, myalgia, arthralgia, nausea, vomiting and chills. For infants and toddlers, events included fever, irritability, crying, sleepiness and loss of appetite."

Among vaccine recipients, these reactions were more common following the second dose of vaccine and resolved within two to three days, Das said, adding that fever was an important assessment of the vaccine's safety for this age group.

Fever after any dose of vaccine occurred in about a quarter of the children -- but fevers occurred more frequently following the second dose -- and one incident of febrile seizure was considered to be related to vaccination, Das told VRBPAC members. The child who experienced the febrile seizure remained in the vaccine study and completed a second dose of vaccine with no serious events.

No deaths, myocarditis or pericarditis were reported among vaccine recipients, Das said.

"In summary, mRNA-1273 was well tolerated," she said, referring to Moderna's vaccine. Local and systemic reactions were seen less frequently in these youngest groups."