Covid-19: Johnson & Johnson's single-dose vaccine 66% effective in large global trial

In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 varied from 72 per cent in the United States

Johnson & Johnson said on Friday that its single-dose vaccine was 66% effective in preventing Covid-19 in a large trial against multiple variants across three continents.

In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 varied from 72 per cent in the United States, to 66 per cent in Latin America and just 57 per cent in South Africa, from where a worrying variant has spread.

A high bar has been set by two authorized vaccines from Pfizer/BioNTech and Moderna, which were around 95 per cent effective in preventing symptomatic illness in pivotal trials when given in two doses.

Those trials, however, were conducted mainly in the United States and before new variants emerged.

J&J’s main goal was the prevention of moderate to severe Covid-19, and the vaccine was 85% effective in stopping severe disease and preventing hospitalization across all geographies and against multiple variants 28 days after immunization.

That “will potentially protect hundreds of millions of people from serious and fatal outcomes of COVID-19,” Paul Stoffels, J&J’s chief scientific officer, said in a statement with the results, which were based on 468 symptomatic cases.

J&J plans to seek emergency use authorization from the U.S. Food and Drug Administration next week.

Public health officials have been counting on the J&J vaccine to increase much-needed supply and simplify the U.S. immunization campaign.

“Right now, any protection and additional vaccine is great. The “South Africa” strain is still uncommon in the U.S. and obviously we would want to see higher efficacy, but the key is not only overall efficacy but specifically efficacy against severe disease, hospitalization, and death,” Walid Gellad, a health policy associate professor at the University of Pittsburgh said of the results.

None of the vaccine recipients in the J&J trial died from COVID-19, compared with 5 deaths in the placebo group, according to the National Institutes of Health, which said there were three deaths in the vaccine group overall, but none were determined to be from the virus.

That compares with 16 deaths overall in the placebo arm.

Unlike the Pfizer/BioNTech and Moderna vaccines, J&J’s does not require a second shot weeks after the first or need to be kept frozen, making it a strong candidate for use in parts of the world with weak transportation infrastructure and insufficient cold storage facilities.

SOUTH AFRICA

Several studies have emerged this month showing that a South African variant of the coronavirus has mutated in areas of the virus that are key targets of vaccines, reducing their efficacy.

“What we are learning is there is different efficacy in different parts of the world,” Stoffels said in a telephone interview.

Importantly, though, in a sub-study of 6,000 volunteers in South Africa, Stoffels said, the J&J vaccine was 89 per cent effective at preventing severe disease. Ninety-five percent of cases in the South Africa portion of the trial were infections with the South African variant.