(CNN) The Biden administration has reached an agreement to purchase 105 million doses of Pfizer's Covid-19 vaccine, the US Department of Health and Human Services announced Wednesday.
The agreement, set for fall vaccinations, includes "options for up to 300 million doses," the agency said in a news release, and adds up to a $3.2 billion contract.
The purchase includes both child and adult vaccines, and may be delivered by early fall, the agency said.
"Vaccines have been a game-changer in our fight against COVID-19, allowing people to return to normal activities knowing that vaccines protect from severe illness," HHS Secretary Xavier Becerra said in the news release. "The Biden-Harris Administration is committed to doing everything we can to continue to make vaccines free and widely available to Americans -- and this is an important first step to preparing us for the fall."
This announcement comes after a fight in recent weeks between the Biden administration and Congress over funding future Covid-19 response and mitigation measures.
The White House had requested $22.5 billion in funding for the administration's Covid-19 response -- money to pay for vaccines, testing, and treatments -- earlier this year. Negotiators had been able to reach a scaled-back agreement on a $10 billion package but left Washington for the Easter recess without passing that bill. Congress has been stalled on reaching a deal ever since.
As a result, $10 billion was reallocated from current Covid-19 response efforts, part of which is being used to fund this new vaccine purchase.
Republican Sen. Mitt Romney of Utah accused the White House of being dishonest about the funding, saying earlier this month that "for the Administration to say they could not purchase these things and then, after several months, divert some funds and then purchase them is unacceptable, and makes our ability to work together and have confidence in what we're being told very much shaken to the core."
Wednesday's announcement also comes a week after vaccinations began in the US for children under 5.
National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci, a member of the federal Covid-19 response, has warned that the US is likely to face an increase in cases in the fall, and US Surgeon General Dr. Vivek Murthy said on CNN's "New Day" last week that the possibility of another booster shot for the broader population in the fall is under discussion.
This story has been updated with additional information.