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 the virus.

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

A handful of other vaccines in the U.S. — including shots made by Moderna Inc. and Pfizer Inc. — and others in other countries are already in final-stage testing. Hopes are high that answers about at least one candidate being tested in the U.S. could come by year's end, maybe sooner.

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

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

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

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

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

And Dr. Anthony Fauci, the top U.S. infectious disease expert, added in the call to governors that he is confident in “a tried and true process”...