▶ Watch Video: COVID vaccine booster shot mixed messaging and confusion over breakthrough cases

The federal government is exercising a clause in its contract with Pfizer to buy 200 million more doses of the COVID-19 vaccine, including for children under 12 if and when the Food and Drug Administration gives the green light and to prepare for the possibility of booster shots, according to an administration official familiar with the contract. 

“Here’s the bottom line — we’ve always prepared for every scenario,” White House press secretary Jen Psaki said Friday, confirming the purchase. 

The doses will be delivered between fall 2021 and spring 2022, as President Joe Biden says the vaccine will likely be available for young children “soon,” and as experts study whether a booster shot might be necessary for fully vaccinated individuals in the future. As a part of the agreement, the official said Pfizer will give the U.S. 65 million pediatric doses if the vaccine is approved for emergency use in children under 12, making doses available immediately in the event of authorization. 

CNN first reported the purchase of the additional 200 million doses. Mr. Biden said the shots would likely be available for young children “soon” during a CNN town hall Wednesday night. 

“Soon, in the sense that I do not tell any scientists what they should do. I do not interfere,” Mr. Biden said, expanding on his answer. “So, they are doing the examinations now, the testing now, and making the decision now.”

For now, on the topic of boosters, public health officials are emphasizing how effective the current vaccine dose regimen is for those who have been fully vaccinated. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told CNN earlier this month that, “given the data and the information we have, we do not need to give people a third shot, a boost.” Still, he said health experts are examining whether a booster shot might be needed in the future.

The conversation about booster shots comes as the Delta variant rages through the U.S., accounting for 83% of all COVID-19 cases. For now, the Centers for Disease Control and Prevention is keeping guidance issued in May — that fully vaccinated individuals do not need to wear masks in most indoor settings, while unvaccinated individuals do.