Moderna (NSDQ:MRNA) announced today that the U.S. government purchased an additional 200 million doses of its COVID-19 vaccine.

The government’s purchase agreement with Moderna also includes the option to purchase other COVID-19 vaccine candidates to come out of the company’s pipeline.

Cambridge, Mass.-based Moderna said in a news release that the purchase brings the U.S. government’s confirmed order commitment to 500 million doses, including 110 million expected to be delivered in the fourth quarter of 2021 and 90 million planned for the first quarter of 2022.

Moderna said that, as of June 14, 2021, it has supplied the U.S. with 217 million released doses of the vaccine. The company is currently seeking full FDA approval for the two-dose vaccine, which in December became one of three to receive FDA emergency use authorization in the U.S.

“We appreciate the collaboration with the U.S government for these additional doses of the Moderna COVID-19 vaccine, which could be used for primary vaccination, including of children, or possibly as a booster if that becomes necessary to continue to defeat the pandemic,” Moderna CEO Stéphane Bancel said in the release. “We remain focused on being proactive as the virus evolves by leveraging the flexibility of our mRNA platform to stay ahead of emerging variants.”