About 18 million children under the age of 5 in the United States could soon be eligible to get a COVID-19 vaccine — but first, the child-sized shot must go through a rigorous authorization process that's taking a different path than the COVID-19 vaccines that came before.

On Tuesday, Pfizer and BioNTech announced that they had initiated a rolling submission to the U.S. Food and Drug Administration of data for their vaccine for children ages 6 months up to 5 years. The companies expect to complete the request for emergency use authorization soon.

It will still go through a thorough safety and efficacy review by U.S. health agencies and experts, but it's a different plan than what was expected late last year.

In December, Pfizer announced that it decided to add a third dose to the primary vaccine regimen for young children. It said the original two-dose series did not provide the expected immunity in 2- to 5-year-olds.

Still, this week's request seeks authorization for the two-dose vaccine, which could make the vaccine available sooner. Pfizer and BioNTech plan to continue testing a three-dose regimen in this younger age group and say they will submit the additional data on a third dose in the coming months.

The company decided to submit for authorization of the two-dose vaccine now "with pediatric COVID-19 cases surpassing 10 million and at the request of the FDA," it said.

"Having a safe and effective vaccine available for children in this age group is a priority for the agency and we're committed to a timely review of the data, which the agency asked Pfizer to submit in light of the recent omicron surge," acting FDA Commissioner Dr. Janet Woodcock said in a news release.

What changed since December

In December, Pfizer said that the vaccines appeared to protect the youngest children — infants and toddlers up to 2 — at the same levels seen in teens and young adults, slashing symptoms in 90% of kids who got the shot. However, the 3-microgram dose did not produce the same immune response in 2- to 5-year-olds.

The dose for infants and young children is about one-third of the dose given to children age 5 to 11 and a tenth the size of the dose given to people 12 and older.

The company decided to expand its trial to include a third dose, rather than the two doses older children and adults receive in a primary vaccine series.

What changed between December and this week's authorization request, public health leaders said, was the omicron variant.

During the omicron surge, cases among children "spiked dramatically," the American Academy of Pediatrics said Monday. There have been over 3.5 million child cases reported in January alone.

"It turns out that has actually facilitated the collection of more important additional clinical data that we did not have in December," U.S. Surgeon General Dr. Vivek Murthy said at a White House COVID-19 briefing Wednesday. "Whether that changes the risk-benefit profile is what the FDA will be assessing, but there has been developments since December on the data front."

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Some suggest that the FDA may be pursing a strategy of authorizing the first two doses of a vaccine that may not offer substantial protection until after a third dose, hoping to start kids on the series even as data on third shots is still pending.

Children have a lower risk of serious outcomes from a COVID-19 infection compared with elderly or immunocompromised adults. But about 1% of children who catch COVID-19 will be hospitalized. Infections can also lead to long-term consequences in children as they do in adults, increasing the risk for diabetes, autoimmune disease and a delayed reaction to infection called multisystem inflammatory syndrome, which requires hospital care.

"If the goal of the vaccine is to get baseline immunity in the kids — to prevent really bad outcomes and you're really not using the vaccine as a tool to prevent infection in the first place — two doses could do that," former FDA Commissioner Dr. Scott Gottlieb, who sits on the board of Pfizer, said on CBS on Sunday. "I think that may be why federal health officials are rethinking this. If, in fact, they decide to authorize this on the basis of two doses, it could be out much sooner, perhaps as early as early March."

Others agree that it could be a smart approach.

"When I was on hospital service last, there was a 7-month-old in the intensive care unit," Dr. Paul Offit, a pediatrician and vaccine expert at Children's Hospital of Philadelphia, told CNN. "If you can prevent that safely, and that's number one, and effectively, number two, then prevent it" with a vaccine.

Offit sits on the panel of experts that advises the FDA on its vaccine authorizations and will be one of the first to review the new data on the vaccine. The FDA's independent vaccine advisers will meet Feb. 15 to discuss the company's data on the youngest children and make a recommendation on the vaccine.

The path to authorization

To authorize COVID-19 vaccines for emergency use, the FDA has previously set a bar of 50% effectiveness, meaning the shots have to prevent disease or decrease severity in at least 50% of the people who get them.

Since the data has not been released, it's unclear whether the Pfizer/BioNTech vaccine for younger children meets that standard after two doses.

Most experts CNN spoke with said they couldn't think of another vaccine review process quite like this.

One somewhat similar example is the Johnson & Johnson vaccine, which was authorized at one dose while the company tested a second, although the first dose proved sufficient to meet the FDA's authorization requirements.

The Pfizer/BioNTech coronavirus vaccine is expected to produce a "good efficacy signal" in children younger than 5, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Wednesday.

"The FDA is looking at the data very carefully, and in their typical fashion, they will be very careful in scrutinizing the data and making a recommendation of the decision based on that data," Fauci said.

That decision to go ahead and ask for the authorization, though, is still considered odd by some health experts.

"This does seem very unusual," said Dr. Eric Rubin, a member of the FDA's vaccine advisory committee and assistant professor microbiology and molecular genetics at Harvard Medical School.

"Regulators have to weigh risk and benefit. And in this case, we know a lot about the risks in older individuals, and they're very low, including older children," Rubin said. "It doesn't have to be that great, as long as we have something that's safe, and then a theoretical benefit could be that you are set up well for future vaccines. But having said all that, it does seem like a very unusual route to take."

Rubin thinks that with so many parents eager to get their kids vaccinated, there may also be some lobbying underway.

"FDA doesn't seem to be immune to political pressures," he said. "And I know that there are some who are saying that it would be good to get a couple doses of vaccine into kids now, in assuming that the third dose is going to be the one that makes a difference."

'We need a vaccine for kids'

Dr. Helen Talbot, an associate professor of medicine at Vanderbilt University and a member of the CDC's independent vaccine advisory board, the Advisory Committee on Immunization Practices, also hasn't seen the data. But she too believes there may be some pressure from parents.

"There's families of kids less than 5 who are really pushing. They feel like they're the last ones that don't have access, and there's nothing available for them," Talbot said. She knows this personally, since she gets a lot of emails asking about it, too.

Talbot said her questions are around safety data and the potential benefits and risks.

She is concerned about people in the middle who aren't quite sure if they want to get their child vaccinated. Only about 3 in 10 parents say they'll get their child under 5 vaccinated against COVID-19 right away, according to survey results from the Kaiser Family Foundation that were released Tuesday.

Communication may be key to help parents understand why they should vaccinate their small children, particularly if two doses may not be as protective as three.

"The FDA is really going to have to be able to eloquently explain the decision," she said.

For his part, Dr. Jay Portnoy, a member of the FDA's advisory panel on vaccines, says he's glad to see the FDA speeding up its process.

"I'm actually relieved," said Portnoy, who's a pediatrician at Children's Mercy Hospital in Kansas City. "Right now, our hospital is filled, not all Covid patients but many COVID patients, including our intensive care unit."

Portnoy says parents are anxious and worried.

"They're forced to send their kids to school, and the schools aren't allowed to mandate masks or anything else," he said."So what is a parent to do? That's just from my perspective. It's about time. We need a vaccine for kids."

What happens after authorization

White House COVID-19 response coordinator Jeff Zients said Wednesday that the administration is ready to "hit the ground running" to vaccinate young children as soon as Pfizer receives a green light from the federal government.

Zients said the U.S. has enough kid-size needles and supplies to administer the vaccines. The administration is also working with local public health partners to make thousands of locations nationwide ready to vaccinate these children.

"We know many parents are eager to get their kids the protection of the vaccine. We know others have questions. So we're working with our partners to ensure all parents have access to the facts and information they need to make the right decision," Zients said.

Pfizer has said it's testing a third dose administered eight weeks after a second dose. Data on a potential third dose, an updated authorization and third-dose rollout would come later on.

This may not be the last change to the COVID-19 vaccine schedule.

Former CDC Director Dr. Tom Frieden said this week that it may be a while before scientists figure out the best vaccine schedule for children.

"What the vaccine schedule should be is much more complicated, and that may take months or even years to optimize," Frieden, president and CEO of Resolve to Save Lives, told CNN's Anderson Cooper.

"It's probably a three-dose schedule for lots of people, but we really don't know that yet," Frieden said. "Nor do we know the right interval between doses. That's going to be with time, but we do know that vaccines are remarkably effective."

For the first time in history, the FDA authorized three e-cigarette products: the Vuse Solo device and its pods.

The agency says the company that makes the Vuse Solo gave them data that shows it can be helpful to cigarette smokers.

In an email, the FDA said, "the potential benefit to smokers who switch completely or significantly reduce their cigarette use would outweigh the risk to youth."

Gregory Conley is the American Vaping Association president.

“After years of debate, you now have the FDA, which is our chief regulatory arm for things that we ingest - The FDA is saying that this particular product is appropriate for the protection of public health,” Conley said.

He says electronic cigarettes, which have been sold in the U.S. since 2006, are an essential step in the fight to help smokers quit tobacco cigarettes.

Last year, the FDA also took steps to keep vape products out of kids' hands, sending warning letters to 10 companies telling them to pull their flavored e-cigarette and e-liquid products because they appeal to young people.

Hasmeena Kathuria, MD, is an associate professor of medicine at Boston University and the director of the tobacco treatment center.

“Inhaling anything directly into the lungs is not a good idea,” Kathuria said.

She says she’s glad the FDA is acting on its promise to regulate these products. Nonetheless, the U.S. Surgeon General's office says since 2014, E-cigarettes have been the most commonly used tobacco product by American kids, and Kathuria says that's concerning.

“We think all e-cigarettes should not be allowed on the market because of – one, the youth epidemic of nicotine addiction, two, we know that there's FDA approved medications for smoking cessation that have that are regulated, that we know are safe, that we know that, that there are effective,” Kathuria said.

Knowing e-cigarettes aren't leaving the market anytime soon, the FDA will make these authorizations and marketing decisions on a case-by-case basis.

The agency says it hopes to get to a place where every vape product is “appropriate for the protection of the public health.”

 

CINCINNATI —

Doctors said more vaccines could soon be weapons in the fight against COVID-19.

The AstraZeneca vaccine is still being carefully studied at Cincinnati Children's Hospital, but it has just been given authorization in the United Kingdom and officials expect to see applications for emergency use in the United States in the next month or so.

Medical experts said AstraZeneca's vaccine could come just in time.

They believe it will be more than capable of defending people against the latest mutation of COVID-19 and it appears to have few side effects.

"I think we soon are going to have four vaccines that look very effective," Dr. Robert Frenck said.

Frenck, professor of pediatrics in the Division of Infectious Diseases at Cincinnati Children's Hospital, shared words of hope.

He expects an application for emergency use authorization could be weeks away for the Oxford University, AstraZeneca COVID-19 vaccine.

It's now authorized in the United Kingdom.

Frenck has been studying the two-dose vaccine at Cincinnati Children's Hospital.

"For both the Pfizer and Moderna, and I wouldn't be surprised to see the exact same thing for Janssen and Astra-Zeneca, is that the vaccine has shown equal efficacy across the ages, and regardless of your race, regardless of your gender," he said.

Frenck said 502 people in Greater Cincinnati have volunteered in the trial.

He said side effects have ranged from nothing to headache, fatigue and muscle aches and those faded.

As a more infectious variant of COVID-19 has surfaced in the United States, Frenck said viruses normally mutate.

The AstraZeneca vaccine uses a weakened version of the common cold virus and he thinks it will work against the mutation.

"It's not really worrying me that much, as far as that the spike protein is what we're having this target for our vaccine and that still looks pretty much conserved," Frenck said.

AstraZeneca's vaccine is receiving praise for only requiring refrigeration which makes it easier to distribute.

Company leaders have said they believe the vaccine will prove as effective as its rivals.

With the Phase 3 trial nearly complete, Frenck anticipates a safe AstraZeneca vaccine will soon be added to the arsenal to protect you.

"To me the biggest travesty, the biggest horror is that we have vaccines and then people don't get them and then people die that could've been saved," he said.

Frenck expects the Johnson and Johnson Janssen vaccine will also be up for emergency use consideration by mid-to-late January.

It's important to note that during the AstraZeneca trial, there were some dosing issues and it is not clear if that will impact the EUA process.

Frenck said timing for the AstraZeneca vaccine will likely be similar to the other vaccines, with a first vaccine given and a second given about four weeks later.

That's to be seen once federal officials receive an application for emergency use and review the data.