Johnson & Johnson launched a new late-stage trial in Britain on Monday to test a two-dose regimen of its experimental COVID-19 vaccine among thousands of volunteers, as the US drugmaker expands its trials by geography and type.

A man wearing a face mask walks on a street in London, Britain, on November 12. Photo: Xinhua

The UK arm of the study is aiming to recruit 6,000 participants among a total of 30,000 people globally, scientists leading the UK trial said. Volunteers will be recruited at 17 sites across the UK.

They will be given a first dose of either a placebo or the experimental shot, currently called Ad26COV2, followed by a second dose or placebo 57 days later, said Saul Faust, a professor of pediatric immunology and infectious diseases who is coleading the trial at University Hospital Southampton.

J&J signed an agreement for the two-dose global Phase III clinical trial with the British government in August, to run in parallel with a 60,000 person trial of a single shot of the experimental vaccine which was launched in September. 

If the results of the single-shot trial are positive, the company said it could simplify distribution of millions of doses compared with leading rivals requiring two doses. The efficacy of a double-dose vaccine could be affected if people fail to return to get their a second shot.

Rival drugmakers Pfizer and BioNtech said on November 9  that their potential COVID-19 shot showed more than 90 percent efficacy in interim data from a late-stage trial.
Newspaper headline: J&J starts trial of COVID-19 candidate vaccine in UK