US drugmaker Pfizer said Thursday it has formally requested emergency use authorization for its Covid-19 vaccine in children age five to 11.

Children have been infected in greater numbers in the latest coronavirus wave driven by the Delta variant, and inoculating young people is seen as key to keeping schools open and helping end the pandemic.

In late September, Pfizer and BioNTech, the German biotechnology giant which co-developed the vaccine, began submitting data to Food and Drug Administration regulators for the highly anticipated authorization.

Pfizer tweeted early Thursday that the two companies had "officially submitted our request" to the FDA "for Emergency Use Authorization (EUA) of our #COVID19 vaccine in children 5 to

"We're committed to working with the FDA with the ultimate goal of helping protect children against this serious public health threat," Pfizer said.

The FDA said last week it had scheduled a meeting of an advisory committee to review the data on October 26, before giving its opinion on whether authorization should be granted.

The Pfizer-BioNTech vaccine has been granted full FDA approval for those age 16 and up
The Pfizer-BioNTech vaccine has been granted full FDA approval for those age 16 and up AFP / DOMINICK REUTER

The agency has previously said that once the formal submission was completed, it would complete its review "likely in a matter of weeks rather than months."

The US Centers for Disease Control and Prevention would subsequently publish recommendations for use for healthcare providers administering the shots.

"If there is approval or authorization, and a CDC recommendation, we are ready, we have the supply," White House Covid coordinator Jeff Zients told CNN following the announcement.

"I think we can all agree that getting a safe and effective vaccine for kids five to 11 is a really important next step in our fight against the virus."

Children in the 5-11 age group received a two-dose regimen of 10 micrograms in the trial, compared with 30 micrograms for older age groups. The shots were given 21 days apart.

The Pfizer vaccine could soon be available for children as young as five in the United States
The Pfizer vaccine could soon be available for children as young as five in the United States AFP / Patrick T. FALLON

The Pfizer-BioNTech vaccine has been granted full FDA approval for those age 16 and up, and the FDA in May authorized its emergency use in children age 12 to 15.

Experts say children are essential to vaccinate to help achieve population immunity against the disease.

While younger children are less likely to develop severe cases, they can still become sick and transmit the virus to the general population.

"We're working with states to set up convenient locations for parents and kids to get vaccinated, including pediatricians' offices and community sites," Zients said.

Nearly 5.9 million children have tested positive for Covid-19 as of September 30, according to the American Academy of Pediatrics.

Vaccines, masks and other mitigation measures against Covid-19 have become deeply political issues in the United States -- especially for children.

California announced just last week that Covid vaccinations will be compulsory for all students, a first in the United States.

About a third of parents with a child between the ages of 5 and 11 say they will vaccinate their kid as soon as possible, according to a Kaiser Family Foundation survey from the end of September.

Another third say they will wait before making a decision, and a quarter say they will not get their child vaccinated.

The Pfizer vaccine received full, formal approval in the US in August and is therefore technically available to children in younger age groups if prescribed by a doctor, but US authorities have cautioned against doing this until the safety data was in.

Health officials are focusing in particular on the risk of myocarditis, an inflammation of the heart muscle that has been found to be more common in young adults and adolescents after vaccination, with an aim of determining whether benefits outweigh risks.

Pfizer and BioNTech are also trialling their vaccine on infants aged six months to two years, and on children aged two to five.

Initial data for these groups may come before the end of the year.

The United States has an estimated 28 million children age five to 11, according to US Census Bureau data from 2019.