Pfizer and BioNTech have asked United States health officials to authorize their Omicron-targeting Covid booster vaccine for children aged 5 to 11, the companies said Monday.
The companies sent a request for emergency authorization for a 10-microgram dose to the US Food and Drug Administration.
If the FDA authorizes the vaccine, the shot will still need another green light from the Centers for Disease Control and Prevention, the country's main federal health agency, before the first injections can be administered to children.
In the coming days, Pfizer and BioNTech will also file for authorization with the European Medicines Agency, they said.
Even though children have been less affected by Covid-19 than adults, several hundred children aged 5 to 18 have died in the United States since the start of the pandemic, according to CDC figures.
In September, the CDC cleared Omicron-specific versions of the Pfizer-BioNTech vaccine for people over the age of 12 and of the Moderna vaccine for those over 18, paving the way for a booster campaign.