Children as young as six months old could be eligible for the Pfizer vaccine by the end of February, according to reports from NBC News.

Federal regulators want to begin gathering data for the two-dose vaccine for children 6 months old to 5 years old - a three-dose regimen is being studied as well.

Regulators believe a three-dose vaccine from children under five could be the answer, but a two-dose vaccine will work for now.

Children under five are the only age group not eligible for a Covid-19 vaccine.

"We’re continuing to collect and analyze data from both two and three doses in our younger age cohort," Pfizer said in a statement.

There are an estimated 19.5 million children under 5 in the U.S.