(Bloomberg) -- President Joe Biden has ordered almost enough Covid-19 vaccine to fully inoculate every American adult twice, expanding production as he faces both uncertainty about domestic needs and calls from shot-starved allies to share the U.S. supply.

Biden announced Wednesday that he’ll double the U.S. order of Johnson & Johnson’s single-dose vaccine to 200 million shots, after the company struck a deal last week with Merck & Co. to boost production.

“A lot can happen, a lot can change, and we need to be prepared,” Biden said at the White House, praising the companies.

Biden’s administration has said its priority is vaccinating every willing American before sending any shots abroad. Wednesday’s announcement shows that the president expects a surplus of vaccine before the U.S. begins to help inoculate the world, beyond contributing billions of dollars to a vaccine program for low-income countries.

Administration officials have defended the U.S. approach, saying a vaccine hasn’t yet been approved for children and it isn’t clear which one will work best for them. Also, they say booster shots may be necessary if the immunity that vaccines provide isn’t long-lasting or doesn’t protect against new variants.

One Biden official, who asked not to be identified discussing a sensitive matter, invoked the country’s death toll -- which stood at 529,000 Wednesday, according to data from Johns Hopkins University. The U.S. has had more Covid deaths than any other country and needs its vaccines to protect against further deaths, the official said.

Vaccine Gap

Nonetheless, Biden’s new order of J&J’s shots risks further exacerbating a vaccine gap between have and have-not nations. Mexico last week asked the U.S. to share doses and was rebuffed, and the European Union has made similar appeals.

Countries that focus on immunizing their own populations face a bitter reality that the pandemic will end only when it ends everywhere. Variants of the virus also tend to emerge when it is spreading unchecked -- raising the chance that a more dangerous version could pop up abroad and then reach U.S. soil.

The EU has exported 34 million doses so far, including nearly a million to the U.S., according to data revealed Wednesday.

Even as Biden said the world will have to wait for help from the U.S., he acknowledged the need.

“We’re going to start off making sure Americans are taken care of, first, but we’re then going to try to help the rest of the world,” Biden said. “We’re not going to be ultimately safe until the world is safe.”

The White House hasn’t said whether any U.S.-produced vaccines have been exported. Moderna Inc. has said its U.S. production is entirely for domestic use. Pfizer Inc. and J&J have declined to say whether they’ve exported any U.S.-produced doses or plan to.

AstraZeneca Plc, whose shot is used widely in Europe but isn’t yet authorized in the U.S., is already producing doses within the U.S.

Both Moderna and Pfizer manufacture their vaccines overseas for international sale.

Production Deal

The agreement between J&J, Merck and the administration will lead to Merck helping manufacture its competitor’s vaccine substance, the active ingredient, and filling vials. The government will pay Merck to overhaul its facilities so that it can help other companies including J&J with production.

The deal between the companies will eventually lead to export of J&J’s vaccine, one U.S. official said.

Biden is “deeply focused on expanding global vaccinations and manufacturing and delivery, which will all be critical to end the pandemic,” White House Press Secretary Jen Psaki said Wednesday.

Doubling the U.S. J&J order means that “for once, we are not only dealing with today, to the best we can, but we are planning for the future,” another Biden adviser, Andy Slavitt, said on MSNBC.

As two of the world’s largest pharmaceutical companies, J&J and Merck have built expansive manufacturing networks to serve global markets -- and both have track records of prioritizing global health. The companies have each developed Ebola virus vaccines, the only drug companies to do so. When the Covid-19 pandemic struck, both set out to make affordable, single-shot vaccines that could be easily stored without advanced freezers.

The companies said that would ease logistical hurdles in getting shots to every corner of the world. But Merck teamed up with J&J after announcing Jan. 25 that its own vaccine candidates had failed -- and after Biden administration officials grew alarmed that J&J appeared to be behind schedule.

Merck’s chairman and chief executive, Ken Frazier, who praised Biden on Wednesday at the White House, has previously criticized nations that sought to hoard vaccines for their own citizens’ use ahead of vulnerable people internationally.

“I would say there are two big issues with respect to global distribution. First of all, we’re living in a time of ultra-nationalism where countries want to take whatever is available and say: I’m going to use it first in my own population, rather than using it first in the populations globally that are at the greatest risk,” Frazier said during an interview with the Harvard Business School in July.

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