• Parents are anxiously awaiting the vaccine for younger children as the omicron variant sweeps across the nation, causing an unprecedented wave of infection over the past month.
• Although children are at much lower risk of developing severe illness from Covid compared to adults, their hospitalizations with the virus have increased during the recent surge of infections, raising concerns about the long-term implications for kids' health.

Pfizer and BioNTech asked the Food and Drug Administration on Tuesday to expand the use of their Covid-19 vaccine to most kids under 5.

The companies said the FDA requested that they start submitting data, which is being submitted on a rolling basis that fast-tracks the approval process, for the authorization of the first two doses of what will eventually be a three-dose vaccine for children six months through 4 years of age. Pfizer and BioNTech said data on the third dose will be completed and submitted to the FDA in the coming months.

Pfizer and BioNTech started submitting their application for emergency approval in response to the "urgent public health need" of younger children as the omicron variant has resulted in a spike in hospitalizations in this age group.

"As hospitalizations of children under 5 due to COVID-19 have soared, our mutual goal with the FDA is to prepare for future variant surges and provide parents with an option to help protect their children from this virus," said Pfizer CEO Albert Bourla in a statement.

Bourla said kids under 5 will ultimately need a third dose to have the best protection against omicron and future Covid variants. By getting the first two-doses FDA authorized, parents can start getting their kids vaccinated while they wait for the third dose, Bourla said. Pfizer and BioNTech expect to complete their application for emergency approval of the first two-doses in the coming days.

Toddlers and kids under 5 years old are the last age group left that is not eligible for vaccination. The FDA is expected to fast track the approval process for 6-month to 4-year-olds like it has for other age groups. Once approved, pediatricians will be able to administer shots within a matter of days.

Parents are anxiously awaiting the vaccine for younger children as the omicron variant sweeps across the nation, causing an unprecedented wave of infection over the past month.

Although children are at much lower risk of developing severe illness from Covid compared to adults, their hospitalizations with the virus have increased during the recent surge of infections, raising concerns about the long-term implications for kids' health.

"Sadly, we are seeing the rates of hospitalizations increasing for children zero to 4, children who are not yet currently eligible for Covid-19 vaccination," Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, told reporters in January.

White House chief medical advisor Dr. Anthony Fauci said last month that he hoped the FDA would authorize the vaccine for kids sometime in February. Fauci said at the time that younger children would likely need a three-dose vaccine.

Pfizer amended its clinical trial in December to study a third shot after two doses of its 3 microgram vaccine did not produce an adequate immune response in children 2 to 4 years old. Adults receive two 30 microgram doses in their primary series of shots.

Pfizer's vaccine researcher, Dr. Alejandra Gurtman, said last month the drugmaker planned to have the data for kids under 5 ready by the end of March or beginning of April. However, a group of 250 doctors sent a letter last month asking the FDA to cut red tape and authorize the 3 microgram dose for children. The doctors said it was unethical to not give parents the option to vaccinate younger children as the pandemic rages across the country.

"As children re-enter daycare centers, preschools, and other unavoidable group settings, we all know that the number of young children infected with omicron will soar exponentially, creating the largest health risk that kids have faced collectively throughout the entire pandemic," the doctors wrote in their letter.

At least 1,000 children have died from Covid since the pandemic began in 2020, according to CDC data, and hospitals have seen more than 94,000 admissions of children with Covid, according to the data. The virus has infected more than 11.4 million children, representing 18.6% of all cases since the pandemic began, according to the American Academy of Pediatrics.

More than 6,000 children have developed multisystem inflammatory syndrome known as MIS-C, according to the CDC. MIS-C is a rare, but serious, condition associated with Covid that is characterized by the inflammation of multiple organ systems. At least 55 children have died from MIS-C, according to CDC data.

 Dr. Grace Lee, a professor of pediatrics at Stanford University, said the pandemic has burdened an entire generation of children, with the long-term impact yet to be seen.

"I also truly believe we have not yet addressed the long-term impact of Covid infection in children," Lee told the CDC's independent committee of vaccines advisors, which she chairs, earlier this month just before the agency cleared Pfizer boosters for 12- to 15-year-old children.

"I think we haven't even scratched the surface of what we're going to see," Lee said.