The Pfizer vaccine would be the only COVID vaccination available for children 6 months to 4 years old.

Pfizer is putting a pause on the approval process for its two-dose Pfizer-BioNTech vaccine for kids under 4.

Health officials had been forecasting an approval date for the vaccine to be near or around February 21. The company was supposed to submit data from clinical trials to the U.S. Food and Drug Administration on February 11 for that approval. Instead, Pfizer said it would be pausing its release of the data and extending the date of the application.

The news comes a couple of days after the CDC told vaccine providers to be prepared to administer doses to the new age group in the last week of February.

In an environment where states continue to announce the lifting of mask mandates, parents are anxious to have access to a vaccine for their babies and preschool-aged children.

In December 2021, Pfizer said data from clinical trials did not produce an immune response that was strong enough in kids aged 2 to 4. Now the company says it wants to wait until it sees results from a third dose before moving forward with an emergency use application. Those results are expected to be available sometime next month.

The clinical trial was conducted with a total of 8,300 children aged 6 months to 12 years from the United States, Finland, Poland, and Spain. Children under 5 were given a smaller dose; 3 µg instead of 10 µg.

Currently, the Pfizer-BioNTech vaccine (also known as COMIRNATY) is available for people age 5 and up in a two-dose regimen. Initially, the doses are given three weeks apart with a booster given five months after the second dose in people 12 and over.

Pfizer currently does not have a new timeline on when it expects to submit the application for preschool-aged children.