Late-stage study of first single-shot vaccine begins in US

Johnson & Johnson is beginning a huge final study to try to prove if a single-dose COVID-19 vaccine can protect against virus.

study starting Wednesday will be one of world's largest coronavirus vaccine studies so far, testing shot in 60,000 volunteers in U.S., South Africa, Argentina, Brazil, Chile, Colombia, Mexico and Peru.

A handful of or vaccines in U.S. — including shots me by Moderna Inc. and Pfizer Inc. — and ors in or countries are alrey in final-st testing. Hopes are high that answers about at least one candidate being tested in U.S. could come by year's end, maybe sooner.

U.S. health officials insist race for a vaccine isn't cutting corners.

“We want to do everything we can without sacrificing safety or efficacy — we’re t going to do that — to make sure that we end up with vaccines that are going to save lives,” Dr. Francis Collins, director of National Institutes of Health, told reporters.

But many vaccine specialists question wher Food and Drug ministration will stick to that goal under intense pressure from Trump ministration. President Donald Trump has consistently presented a faster timeline for a new vaccine than experts say is equate to fully test candidates.

Meanwhile, testing of still ar experimental vaccine, me by AstraZeneca, remains on hold in U.S. as officials examine a safety question, even though studies have resumed in or countries.

Earlier this week, Vice President Mike Pence urged state goverrs to "do your part to build public confidence that it will be a safe and effective vaccine.”

And Dr. Anthony Fauci, top U.S. infectious disease expert, ded in call to goverrs that he is confident in “a tried and true process” that has checks and balances built in, including an independent board evaluating progress of each vaccine trial, as well as “ integrity of FDA.”

A recording of call was provided to Associated Press.

Senators were scheduled to question FDA Commissioner Stephen Hahn, Fauci and or ministration officials later Wednesday about pandemic response.

Even if FDA were to allow emergency use of a vaccine by year's end, supplies would be limited and given first to vulnerable groups such as health workers. Most Americans aren't likely to receive a vaccine until sometime next year.

Centers for Disease Control and Prevention wants states to get rey w to roll out vaccinations, which will present ermous logistical challenges. On Wednesday CDC was set to anunce distribution of $200 million in congressionally approved funds to help begin setting up operations.

Health and Human Services Secretary Alex Azar said COVID-19 vaccine campaign will build on longstanding cooperation between federal government and states on immunizations.

J&J's vaccine is me with slightly different techlogy than ors in late-st testing, modeled on an Ebola vaccine company created. Unlike or three vaccines that started late-st testing in U.S., it requires only one shot, t two. Despite a later start to testing than some of its competitors, Dr. Paul Stoffels, J&J's chief scientific officer, told reporters that study was large eugh to yield answers possibly by early next year.