WASHINGTON (NewsNation Now) — Pfizer will supply the U.S. with 100 million additional doses of its COVID-19 vaccine by July next year, the drugmaker said on Wednesday.

The agreement brings the total number of Pfizer doses to be delivered to the United States to 200 million, allowing for 100 million people to be vaccinated.

Pfizer and German partner BioNTech SE will deliver at least 70 million doses by June 30, with the balance of the 100 million doses to be delivered no later than July 31, the company said.

The U.S. government will pay $1.95 billion for the additional 100 million doses, bringing the total paid to Pfizer to nearly $4 billion.

The government already has a deal with Pfizer for 100 million doses of the vaccine, which are being rolled out across the country after the shot won emergency use authorization earlier this month.

Pfizer’s vaccine was the first to gain approval from the Food and Drug Administration and initial shipments went to states last week. It has now been joined by a vaccine from Moderna, which was developed in closer cooperation with scientists from the National Institutes of Health.

Moderna’s vaccine comes under the umbrella of the government’s own effort, which is called Operation Warp Speed. That public-private endeavor was designed to have millions of vaccine doses ready and available to ship once a shot received FDA approval.

But another deal with Pfizer moves the nation closer to the goal of vaccinating all Americans.

Health and Human Services Secretary Alex Azar said last week that the government was negotiating with Pfizer for more doses, but new details were revealed Tuesday about the company’s desire for better access to supplies.

The vaccine from Pfizer and German pharmaceutical BioNTech immediately raised hopes of taming a pandemic that has killed nearly 320,000 people in the U.S. and hobbled much of the national economy. Health care workers and nursing home residents topped the list as local TV stations across the country began broadcasting scenes of the first vaccinations. Some polls show skepticism about getting vaccinated may be easing.

After early failures with testing, Trump administration officials are hoping to write a very different ending with vaccines. Operation Warp Speed has financed the development, manufacture and distribution of millions of doses, with the goal of providing a free vaccine to any American who wants one.

Operation Warp Speed is on track to have about 40 million doses of vaccine by the end of this month, of which about 20 million would be allocated for first vaccinations. Distribution of those doses would span into the first week of January. Both the Pfizer and Moderna vaccines require two shots to be fully effective.