WASHINGTON — The Biden administration, under pressure to increase the supply of coronavirus vaccines to poor nations, plans to spend billions of dollars to expand manufacturing capacity, with the goal of producing at least one billion additional doses a year beginning in the second half of 2022.

The investment is part of a new plan, announced Wednesday by White House officials, for the government to partner with industry to address immediate vaccine needs in the United States and overseas and to prepare for future pandemics. It comes on top of recent decisions to buy enough of Pfizer’s new Covid-19 pill for about 10 million courses of treatment, and to spend $3 billion on rapid over-the-counter tests, which are needed to detect the virus early enough for the Pfizer drug to work.

Taken together, the moves amount to an expansive new effort to control the pandemic at a time when Americans are desperate for normalcy and caseloads are creeping up with winter’s approach.

In another development that the White House hopes will reassure the public, the Food and Drug Administration is likely to approve requests from Pfizer-BioNTech and Moderna to offer booster shots to everyone 18 and older.

President Biden has pledged to fight the coronavirus pandemic by making the United States the “arsenal of vaccines” for the world. But national self-interest is also at work; as long as vaccination rates remain low in other parts of the world, allowing the virus to spread, dangerous new variants could arise and plunge the United States into crisis once again.

The global need is great. Testifying on Capitol Hill on Wednesday, Loyce Pace, the director of global affairs at the Department of Health and Human Services, said that more than half of the world’s five million coronavirus deaths had occurred in low- and middle-income countries, and that vaccination rates in some of them “are in the single digits.”

Less than 10 percent of Africa’s population is vaccinated, she said, compared with more than 50 percent in North America and Europe. In many poor nations, including those struggling to combat other diseases like tuberculosis, malaria and H.I.V., even health care workers on the front lines of the pandemic remain unvaccinated.

Expanding vaccine manufacturing through public-private alliances is not without risks. Until recently, the federal government had a manufacturing partnership with Emergent BioSolutions, whose Baltimore facility ruined millions of doses of Johnson & Johnson’s coronavirus vaccine earlier this year. The Biden administration severed its relationship with Emergent earlier this month.

Administration officials insist this plan will be different. In interviews, Jeff Zients, President Biden’s coronavirus response coordinator, and Dr. David Kessler, who oversees vaccine distribution as the chief science officer for the Covid-19 response, said the intent is to invest in companies with experience making mRNA vaccines, enabling those companies to expand production to meet the government’s needs.

That could include building new plants or production lines, and it might require licensing technology from other vaccine manufacturers.

“This is about assuring expanded capacity against Covid variants and also preparing for the next pandemic,” Dr. Kessler said in an interview. “The goal, in the case of a future pandemic, a future virus, is to have vaccine capability within six to nine months of identification of that pandemic pathogen, and to have enough vaccines for all Americans.”

Dr. Kessler and Mr. Zients conceded the plan is not fully fleshed out; the Biomedical Advanced Research and Development Agency on Wednesday issued a request for ideas from industry. The price tag is unknown; Dr. Kessler estimated it at several billion, with the money coming from the American Rescue Plan, the $1.9 trillion coronavirus relief package Mr. Biden signed into law earlier this year.

Mr. Zients said the government was looking to move quickly, and wanted responses from industry within 30 days. The potential partners appear to be limited; only two major vaccine makers — Pfizer and Moderna — are currently using mRNA technology, although those companies employ contract manufacturers to do the work for them.

In a statement on Wednesday, Pfizer commended the administration and pledged to “come to the table with how we can best contribute” to the fight against Covid-19. Officials at Moderna did not respond to an email message seeking comment. But Steve Brozak, an investment banker whose company, WBB Securities, specializes in biotechnology, said engaging industry could prove difficult.

“Without a specific commitment of money, without a specific time plan, companies may not be interested,” Mr. Brozak said. If the administration wants to ramp up vaccine manufacturing, he added, it will also have to increase production of resins and other vaccine components.

Reaction to the plan was mixed, especially among activists who have been pushing the Biden administration to lean on Pfizer and Moderna to share their technology with manufacturers overseas. (The National Institutes of Health is in a patent dispute with Moderna, which received billions in taxpayer funding, over who deserves credit for inventing the central component of the company’s coronavirus vaccine.)

“The idea of making a business plan with two companies rather than a public health plan is disturbing to us,” said Dr. Joia Mukherjee, chief medical officer of Partners In Health, a global public health nonprofit. “We believe that Biden has the power, particularly with Moderna because so much of it was taxpayer funded, to demand the sharing of patents and know-how.”

Some activists, furious with what they regard as the administration’s slow progress, turned up at the home of Ron Klain, Mr. Biden’s chief of staff, in September and deposited a fake mountain of bones on the sidewalk in protest. Another group protested outside Mr. Zients’s home on Wednesday morning.

Addressing criticism that the Biden plan is not focused on building capacity overseas, Dr. Kessler said that domestic manufacturing “is important not only for the U.S. supply, but for global supply.”

At the same time, partnering with big drug makers offers no guarantees. Mr. Biden announced earlier this year that he had brokered a deal with Merck & Co., the pharmaceutical giant, to manufacture Johnson & Johnson’s vaccine, including for other countries. Officials hailed the partnership as historic, saying it fit in with the president’s vision of a manufacturing campaign like the one Franklin D. Roosevelt spearheaded to produce supplies for World War II.

But the Merck deal has not panned out as expected. Administration officials initially hoped Merck would begin producing the vaccine’s key ingredient by the end of this year, but that will not happen until April, Dr. Kessler said.

Congress put a total of $16.05 billion in the American Rescue Plan this year, in two separate tranches, that could be used to procure and manufacture treatments, vaccines and other tools for ending the pandemic.

But in an analysis released this summer, the AIDS advocacy group Prep4All found that all told, the administration had spent $145 million — just $12 million of it from the American Rescue Plan — to expand vaccine manufacturing. Most went to retrofitting Merck’s production lines.

James Krellenstein, a founder of Prep4All and the author of the study, pointed to the experience with Emergent and Merck to suggest that simply paying industry to build new production lines will not work. His group has called for the government to build its own vaccine manufacturing facility, and to hire a contract manufacturer to run it.

“The Biden administration is at two forks in the road right now,” Mr. Krellenstein said. “We have to commend them in the first place for committing to address seriously the manufacturing and supply issues. But we do need the Biden administration to learn a little bit from history.”

The advocacy group Public Citizen has called for a $25 billion government investment to make eight billion doses of mRNA in one year, enough to meet global need. Peter Maybarduk, Public Citizen’s access to medicines director, criticized the administration for not doing more to press Moderna and Pfizer to share their technology with manufacturers in developing nations.

“Sharing doses is charity, and desperately needed,” he said. “But sharing knowledge is justice.”