Pfizer and BioNTech have submitted an application to the US Food and Drug Administration for their updated Covid-19 vaccine to be used as the third shot in the three-dose primary vaccine series for children ages 6 months through 4 years.
The vaccine makers announced on Monday that if authorized for emergency use, children in that age group will still receive the original version of the Covid-19 vaccine as their first two doses and then the updated Covid-19 vaccine – formulated to target the coronavirus Omicron subvariants BA.4 and BA.5 – as the third dose.
While the primary Covid-19 vaccine series for older children and adults involves receiving two doses of the Pfizer/BioNTech vaccine, a three-dose primary series has been the approach for children younger than 5.
The Omicron-adapted vaccine is currently authorized for emergency use in the United States as a booster dose for people 5 and older.
“With the high level of respiratory illnesses currently circulating among children under 5 years of age, updated COVID-19 vaccines may help prevent severe illness and hospitalization,” according to the companies’ announcement on Monday morning.
Pfizer and BioNTech’s application for use of the vaccine in younger ages comes as respiratory illnesses – including RSV, flu and Covid-19 – are on the rise and overwhelming hospitals across the United States.
In a letter to the nation’s governors Friday, US Health and Human Services Secretary Xavier Becerra noted that flu and other respiratory viruses are “increasing strain” on the country’s health care systems.
In the letter, obtained exclusively by CNN, Becerra wrote that the Biden administration “stands ready to continue assisting you with resources, supplies, and personnel.”
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There is no vaccine for RSV, but health officials have urged people to get their flu shots and updated Covid-19 boosters heading into winter.
In general, Covid-19 vaccinations have been slow among young children. According to data from the US Centers for Disease Control and Prevention, less than 5% of children younger than 5 are fully vaccinated against the coronavirus, having completed their primary series of vaccinations. Among people ages 5 and older, 73% are vaccinated, and 13% are vaccinated and boosted.
CNN’s Deidre McPhillips contributed to this report.