WASHINGTON (AP) — U.S. officials said Tuesday they expect health insurance companies will cover vaccines for COVID-19 without charging copays, once those vaccines are developed and become available.

At a briefing for reporters, a senior Trump administration official said the government has been talking with insurers about offering vaccines at no cost to patients. The industry earlier made a similar commitment to cover testing for the coronavirus without charging copays.

The White House has launched an initiative to quickly manufacture millions of doses of COVID vaccines, once the Food and Drug Administration approves one or more formulations.

Candidate vaccines are in early trials, and the goal — considered ambitious — is to have 300 million doses by early next year. At the White House signing of an executive order on policing, President Donald Trump predicted it could even be met before the end of this year. Dr. Anthony Fauci of the National Institutes of Health has said a vaccine by year’s end is conceivable only if everything goes right in final testing this summer.

Earlier Tuesday, senior administration officials provided an overview of the effort to rapidly manufacture, distribute and deliver eventual vaccines. The officials spoke on condition that they not be publicly identified.

The White House has dubbed the initiative “Operation Warp Speed,” a joint project of the Department of Health and Human Services and the Pentagon, under the overall direction of HHS. The Defense Department has extensive medical capabilities to keep U.S. service members worldwide safe from disease.

As with other vaccines, U.S. insurers will have a strong financial interest in covering one for COVID-19. Vaccines are seen as a win-win, helping the insurers' customers stay healthy by preventing disease, which in turn can save the companies money.

Administration officials told reporters Tuesday that the COVID-19 vaccine, once available, will be distributed according to priorities, with the most vulnerable people ahead in line. The coronavirus has taken a disproportionate toll on older people and those with other underlying conditions such as high blood pressure and diabetes. Not all Americans will have to be vaccinated, because it's expected that millions will be protected by their own antibodies.

Health insurers cover vaccines recommended by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices. They're considered a preventive service, and the Affordable Care Act requires insurers cover them at no charge to patients. A range of screening tests, immunizations and birth control for women are already covered under the Obama-era Affordable Care Act. However, the Trump administration is pressing the courts to overturn “Obamacare” as unconstitutional.

At the White House, Trump exuded optimism, not dwelling on potential complications, whether legal or scientific.

“I predict we will have a very successful vaccine, therapeutic, and cure,” said the president. “We’re making tremendous progress. I deal with these incredible scientists, doctors, very, very closely. I have great respect for their minds.”