UK's COVID-19 study aims to vaccinate more than 10,000

LONDON (AP) — British researchers testing an experimental vaccine against the new coronavirus are moving into advanced studies and aim to immunize more than 10,000 people to determine if the shot works.

Last month, scientists at Oxford University began vaccinating more than 1,000 volunteers in a preliminary study designed to test the shot’s safety. Those results aren't in yet but on Friday, the scientists announced they're expanding to 10,260 people across Britain, including older people and children.

If all goes smoothly, "it's possible as early as the autumn or toward the end of the year, you could have results that allowed use of the vaccine on a wider scale," predicted Andrew Pollard, head of the Oxford Vaccine Group.

But Pollard acknowledged there were still many challenges ahead, including how long it will take to prove the vaccine works — particularly since transmission has dropped significantly in Britain — and any potential manufacturing complications.

The Oxford shot is one of about a dozen experimental vaccines in early stages of human testing or poised to start, mostly in China, the U.S. and Europe. Scientists have never created vaccines from scratch this fast and it’s far from clear that any of the candidates will ultimately prove safe and effective.

Moving on to such a huge late-scale test doesn't guarantee the Oxford candidate will reach the finish line, either. Pollard couldn't provide any data from the first tests, but said an oversight board hasn't seen any indications of worrisome side effects.

A small study in monkeys offers a note of caution: The Oxford team and researchers from the U.S. National Institutes of Health found the vaccine protected against pneumonia but didn't eliminate the coronavirus in the nose. Pollard said it was still an open question whether the shot could make a...