The US is expected to approve coronavirus vaccines for children under the age of five by the end of February.
Officials at the Food and Drug Administration FDA anticipate Pfizer will ask them in coming days to authorise two doses for the age group.
The company is also researching a three-dose regimen but that data is not likely to be submitted until March.
Paediatric Covid-19 cases have spiked since the rise of the Omicron variant.
According to the American Academy of Pediatrics, more than 3.5 million cases were reported in the US last month.
