The U.S. Food and Drug Administration's outside vaccine advisers have voted unanimously that two COVID-19 vaccines — Moderna and Pfizer-BioNTech — for children between six months and five years of age should be authorized.
For both vaccines, the 21 advisers voted on the question of whether the benefits outweigh the risks.
Young children are the only group that has remained ineligible for immunization during the pandemic.
Health Canada is also reviewing Moderna's COVID-19 vaccine for younger children. Canada has not yet received an application for that age group from Pfizer.
There is no word yet when a decision will be made in Canada.
WATCH | Moderna's vaccine for younger children under review:
Kid-sized shots may be available next week in U.S.
The U.S. FDA reviewers said both brands appear to be safe and effective for children as young as six months old in analyses posted ahead of the all-day meeting. Side effects, including fever and fatigue, were generally minor in both, and less common than seen in adults.
If the FDA agrees with its advisers and authorizes the shots, there's still one more step. The U.S. Centers for Disease Control and Prevention (CDC) will decide on a formal recommendation after its own advisers meet Saturday.
If the CDC signs off, kid-sized shots could be available as soon as Monday or Tuesday at doctors' offices, hospitals and pharmacies in the U.S.
Moderna's vaccine for younger children will be one-quarter the size of its adult formulation and Pfizer-BioNTech's will be one-tenth of its grownup size.
During trials, Pfizer-BioNTech found that those two doses didn't offer enough protection against Omicron, so it will be a three-dose vaccination course. Moderna's will be two doses, although the company has added a booster to its pediatric studies and is expected to offer that third dose in the future.
Pfizer-BioNTech's vaccine is for children six months through four years of age; Moderna's vaccine is for six months through five years.
'Troubling surge' in child hospitalizations during Omicron
Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, opened Wednesday's meeting with data showing a "quite troubling surge" in the hospitalization of young children during the Omicron wave, and noted 442 children under four have died during the pandemic in the U.S.
That's far fewer than adult deaths, but should not be dismissed in considering the need for vaccinating the youngest children, he said.
"Each child that's lost essentially fractures a family," Marks said.
Dr. Arwa Nasir, a professor of pediatrics at the University of Nebraska Medical Center, told CBC News that making the vaccine available to young children is "very important" in protecting them from COVID-19.
"Kids under five, you know, they can't mask as well. Their hand, mouth and hygiene habits are not as established as with adults. So transmission does happen very highly in this patient population," Nasir, who was not on the FDA advisory panel, said on Wednesday.
"Anything that could prevent a potential bad infection with very, very low risk of side effects, I think is hard to argue against," she said.
Canadian parents waiting
In an emailed statement to CBC News on Wednesday, Health Canada said that because its review of Moderna's pediatric vaccine for younger children is still ongoing, "it is not possible to predict when a regulatory decision will be made."
Although some parents are unsure whether they will vaccinate their young children, others are waiting anxiously for it to be available in Canada, said Dr. Fatima Kakkar, a pediatric infectious diseases specialist at CHU Sainte-Justine in Montreal.
"It is coming," Kakkar told CBC News, noting that advisory groups are reviewing the data in real time and rollout should not take too long if the little kid-sized vaccine gets Health Canada approval.
She hopes the fact that the approval process takes time will reassure vaccine-hesitant parents that experts consider the risks and benefits very carefully before making recommendations.
"This is that only group that we haven't been able to offer protection for and that we don't have great treatments for if they get COVID," Kakkar said.
"In the big picture … it's protection for this group, but it also minimizes the risk to others, because the less … infection, the less circulation, the less reinfection to other vulnerable members. But the priority and the reason for giving it to these children is to protect them from severe disease and severe outcomes."