The U.S. has already manufactured and stockpiled "hundreds of thousands of doses" of coronavirus vaccines in the hopes that one will be effective in combating the virus, a senior administration official said Tuesday.
The Trump administration's Operation Warp Speed has doses -- none of which have been approved or authorized for use -- from three companies the U.S. government already paid for the vaccine manufacturing process. Should the Food and Drug Administration give them clearance, the vaccines would be ready to be deployed.
The official declined to specify which companies had manufactured the three different vaccine types.
“As I mentioned manufacturing is already underway for three of our vaccines," Paul Mango, Health and Human Services deputy chief of staff, said last week. "We already have manufacturing started for the other three. We are retrofitting a number of facilities.”
Mango said the U.S. expects to have four coronavirus candidate vaccines in large-scale clinical trials by the middle of September. The government is "very pleased" with the progress, he said.
President Trump unveiled an ambitious $10 billion program in mid-May to develop, produce and distribute a COVID-19 vaccine by the end of the year, with the goal of making "at least" 300 million doses to administer to Americans.
Globally, there are about a dozen vaccine candidates in the first stages of testing or about to begin. Some of the notable ones that have garnered attention include those created by biotech company Moderna and a different one from Oxford University.
The U.S. has the highest number of confirmed COVID-19 cases in the world, totaling more than 6 million. As of Tuesday, the virus had killed 183,733 individuals in the nation, according to Johns Hopkins University data.
FOX Business' Edward Lawrence contributed to this report