Pfizer and BioNTech have submitted an application to the US Food and Drug Administration (FDA) for the emergency use of their Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine as a booster dose for children aged six months to four years.
The vaccine is already authorised as the third dose of the three-dose primary series for children in this age group, but the companies say a fourth dose would ‘give families the option to further protect their young children against more recently circulating Omicron sub lineages’.
If the FDA approves their application, children in this age group who have completed their primary series – either with three doses of the companies’ original vaccine or with two doses of the companies’ original and one dose of the bivalent vaccine – would be able to receive a 3µg booster dose of the bivalent vaccine after at least two months.
The latest US submission is supported by data showing a fourth dose of the bivalent booster elicited a higher Omicron BA.4/BA.5 neutralising response in children aged six months to four years, compared to those who received three doses of the companies’ original vaccine.
Pfizer and BioNTech also said that, in addition to their US application, they plan on making submissions to the European Medicines Agency and other regulatory authorities worldwide for use of the bivalent vaccine as a booster dose for children under five.
The adapted vaccine is already authorised as a booster dose for those aged five years and older in both the US and EU.
Vaccine manufacturers have been focused on the development of variant specific boosters since the World Health Organization recommended that COVID-19 vaccines be reworked to ensure they are effective against Omicron and future variants.
Moderna received emergency use authorisation from the FDA in December last year for its BA.4/BA.5 Omicron-targeting bivalent COVID-19 booster vaccine, mRNA-1273.222, for children aged from six months to five years.
The authorisation, which is based on a 10μg booster dose following a completed primary series of the company’s original vaccine, was supported by clinical trial booster data for its original Spikevax vaccine, pre-clinical data for the booster and clinical trial data for its second Omicron-targeting bivalent booster, mRNA-1273.214.