The U.S. government agreed to pay nearly $2 billion for a promising COVID-19 vaccine being developed in the Lower Hudson Valley.

On Tuesday, Pfizer Inc and BioNTech SE announced an agreement with the U.S. Department of Health and Human Services and the Department of Defense to meet the U.S. government’s Operation Warp Speed program goal to begin delivering 300 million doses of a vaccine for COVID-19 in 2021.

Under the agreement, the U.S. government will receive 100 million doses of BNT162, the COVID-19 vaccine candidate jointly developed by Pfizer and BioNTech, after Pfizer successfully manufactures and obtains approval or emergency use authorization from U.S. Food and Drug Administration.

The U.S. government will pay the companies $1.95 billion upon the receipt of the first 100 million doses, following FDA authorization or approval. The U.S. government also can acquire up to an additional 500 million doses.

“Expanding Operation Warp Speed’s diverse portfolio by adding a vaccine from Pfizer and BioNTech increases the odds that we will have a safe, effective vaccine as soon as the end of this year,” HHS Secretary Alex Azar said in a press release. “Depending on success in clinical trials, today’s agreement will enable the delivery of approximately 100 million doses of this vaccine to the American people.”

Americans will receive the vaccine for free consistent with the U.S. government’s commitment to free access for COVID-19 vaccines, officials say.

“We’ve been committed to making the impossible possible by working tirelessly to develop and produce in record time a safe and effective vaccine to help bring an end to this global health crisis,” Pfizer Chairman and CEO Dr. Albert Bourl said. “We made the early decision to begin clinical work and large-scale manufacturing at our own risk to ensure that product would be available immediately if our clinical trials prove successful and an Emergency Use Authorization is granted. We are honored to be a part of this effort to provide Americans access to protection from this deadly virus.”

The BNT162 program is based on BioNTech’s mRNA technology and supported by Pfizer’s vaccine development and manufacturing capabilities. The companies are developing four potential COVID-19 vaccines, each of which represents a unique combination of messenger RNA (mRNA) format and target antigen. Recently, two of the companies’ four investigational vaccine candidates (BNT162b1 and BNT162b2) received Fast Track designation from the U.S. Food and Drug Administration (FDA).

In July, the companies announced preliminary data from BNT162b1, the most advanced of the four potential vaccines, is able to produce neutralizing antibodies in humans at or above the levels observed in the plasma from patients who have recovered from COVID-19, and this was shown at relatively low dose levels, officials say.

According to Rockland County Executive Ed Day, most of Pfizer's work on a COVID-19 vaccine is being done in Rockland County.

"One more time I am ready to burst with pride as Rockland again is leading the way during a time of crisis. We did it last year during the measles outbreak, saving our nation's measles free designation by the World Health Organization. Now we are on the forefront of developing the vaccine for COVID-19. Kudos to the Pfizer vaccine development team," Day wrote on Facebook. "It is right here in Pearl River where the majority of Pfizer’s R&D efforts to support this vaccine are taking place. Thank you to everyone at Pfizer's Pearl River site for their hard work developing a possible vaccine."

Pfizer believes they are on track to begin a safe trial later this month, seek regulatory review as early as October 2020, and manufacture globally up to 100 million doses by the end of 2020, officials say.