The US government has bought another 200 million doses of Moderna's Covid-19 vaccine, the drugmaker said on Wednesday, including an option to buy experimental shots that may be in development.
The additional Moderna doses, which brings total US orders to 500 million, could be used for primary inoculation, including of children, or as a possible booster shot, the company said.
Moderna is currently conducting clinical trials testing a third booster shot of its authorized vaccine as well as an experimental one to protect against coronavirus variants.
The US government last August signed a $1.53 billion deal with Moderna for 100 million vaccine doses, with an option to buy 400 million more.
The company has filed for a full US approval of the Covid-19 vaccine currently being used and has also asked regulators to authorize its emergency use in adolescents aged 12 through 17.
US President Joe Biden had set a goal to vaccinate 70% of American adults with at least one Covid-19 shot by the July 4 Independence Day holiday, although the pace of vaccination has slowed significantly since April.
The latest purchase also comes just a week after the Biden administration said it planned to donate 500 million Pfizer vaccine doses to nearly 100 countries amid concerns of disparity in inoculations between advanced economies and developing countries.
Moderna, which has supplied 217 million doses of its shot to the US government as of Monday, said the additional purchase was to ensure continuous supply through the first quarter of next year. The company said it was set to deliver 110 million doses in the fourth quarter and 90 million in the first quarter of 2022.