The Biden administration’s purchase of 200 million additional Pfizer and Modern doses means the U.S. could fully vaccinate 300 million people with just those two vaccines — and 355 million more people if four additional vaccines gain FDA approval.

Why it matters: The U.S. is home to 250 million adults, many of whom won’t elect to be vaccinated. It’s also now in control of a big chunk of the global vaccine supply. The White House says the U.S. will eventually donate excess doses to other countries, but it hasn’t released a plan to do so.

The state of play: The administration has been focused almost entirely on ensuring that every American who wants a vaccine will be able to get one by this summer.

• With the additional Pfizer and Moderna doses — and up to 40 million Johnson & Johnson doses ready to be deployed if approved — the White House is increasingly confident they’ll reach that goal.
• In the meantime, the administration will “develop a framework to supply surplus doses … including through the COVAX facility as appropriate,” says State Department spokesman Ned Price.
• They’ll have to balance distributing doses around the world with holding them back for potential booster shots or the vaccine hesitant.

Between the lines: Sources in the administration emphasize that despite the bulk orders, only two vaccines have been approved and supplies remain scarce on the ground. Until that changes, they say, it’s too early to focus on sharing doses globally.

The state of play: Many countries’ vaccination plans rely entirely on the global COVAX initiative, which aims to distribute two billion doses this year, mainly to low and middle-income countries. Some don’t expect to vaccinate the bulk of their population until 2023.

• COVAX is developing a platform for donations, which it expects to ramp up in the second half of 2021 as wealthy countries start to meet their domestic needs, according to a spokesman for Gavi, the international vaccine alliance.
• Biden has said the U.S. will participate in COVAX, which Donald Trump snubbed, but has yet to provide specific commitments.
• Countries including Canada and France have said they’ll contribute doses to COVAX, but only Norway has promised to do so in parallel with its domestic vaccination program.

Meanwhile, India and China are making bilateral donations to neighboring countries, while China and Russia are selling their state-funded jabs all over the world.

• White House Press Secretary Jen Psaki warned on Friday that China and Russia could use vaccines to make other countries beholden to them.
• She has also stressed that the U.S. committed $4 billion to Gavi in December for global vaccinations, and Biden’s recovery plan includes $11 billion more for the global relief effort.
• Canada and the U.K. have actually purchased even more doses relative to their populations than the U.S., but the U.S. controls the most total doses.

What they’re saying: “From a U.S. perspective, we’re losing a bit of the messaging war out there,” says Dr. Krishna Udayakumar, director of Duke University’s Global Health Innovation Center.

• “If we look six months from now, it may well be the fact that the U.S. has donated more doses than any other country in the world. But right now the storyline is how we’re buying more and hoarding more of the supply.”

Dr. Zeke Emanuel, vice provost for global initiatives at the University of Pennsylvania, acknowledges that the bulk purchases have sparked international criticism, but says things will look much different in the spring. By then, the U.S. will have ramped up domestic distribution and be able to think more about supplying doses globally.

• Emanuel, who served on Biden’s COVID-19 advisory board during the transition, says that as one of the world’s biggest biggest coronavirus hotspots — and its biggest economy — the U.S. should be a priority country for vaccination under any circumstances.
• He also says that the billions invested by the U.S. could help expand global vaccine production in the longer term.
• For now though, “every time a bilateral deal gets struck it means capacity is taken out that could go towards supporting equitable access,” the Gavi spokesman said.

The bottom line: As Dr. Anthony Fauci has noted, the emerging variants of COVID-19 underscore the necessity of efficiently distributing vaccines all over the world to truly get the pandemic under control.

• The U.S. “will be a part of that process,” Fauci says. But it’s not yet clear what America’s role will be.

Worth noting: Most of the 1.2 billion doses of six vaccines currently on the books were purchased as part of the Trump administration’s Operation Warp Speed. Sanofi’s isn’t on our chart because it’s not expected until late 2021.