Mila Pagador, 5, speaking to registered nurse Ashley Bean before she received her dose of the Pfizer-BioNTech Covid-19 vaccine in Albuquerque, N.M., last year.Credit...Paul Ratje for The New York Times

Pfizer and BioNTech in mid-December announced that two doses of the vaccine, given at a tenth of the amount of an adult dosing, did not produce a strong enough immune response in children ages 2 to 4.

Pfizer and its partner BioNTech are expected as soon as Tuesday to ask the Food and Drug Administration to authorize a coronavirus vaccine for children 6 months to 4 years old as a two-dose regimen while they continue to research how well three doses works.

Federal regulators are anxious to review the data in hopes of authorizing shots for young children on an emergency basis as early as the end of February, according to multiple people familiar with the discussions. If Pfizer waited for data on a three-dose regimen, the data would not be submitted until late March and the vaccine might not be authorized for that age group until weeks later, according to multiple people familiar with the situation.

Federal officials and Pfizer executives had been suggesting for days that an application for emergency authorization of a vaccine for the youngest children was in the works. Scott Gottlieb, a Pfizer board member and former commissioner of the Food and Drug Adminstration, told CBS News on Sunday that the vaccine might be authorized as soon as March. The development was first reported by The Washington Post.

As the Omicron variant has swarmed the country, there has been a sharp increase in pediatric cases of the virus, according to the American Academy of Pediatrics, which gathers state-level data. Even though young children tend to do well combating the virus, some can get very ill. Federal officials were anxious to begin a vaccination program for the youngest children because the studies showed there were no safety concerns with two doses.

Pfizer and BioNTech in mid-December announced that two doses of the vaccine, given at a tenth of the amount of an adult dosing, did not produce a strong enough immune response in children ages 2 to 4.

Source: https://www.nytimes.com/2022/01/31/science/pfizer-is-expected-to-ask-the-fda-to-authorize-its-covid-vaccine-for-children-under-5.html?campaign_id=60&emc=edit_na_20220131&instance_id=0&nl=breaking-news&ref=headline&regi_id=159699358&segment_id=81276&user_id=57103be3843e0e1cb6615f5efa797221