Johnson & Johnson said on Friday that its single-dose vaccine was 66% effective in preventing COVID-19 in a large global trial against multiple variants.
In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 varied from 72% in the United States, to 66% in Latin America and just 57% in South Africa, from where a worrying variant has spread.
A high bar has been set by two authorised vaccines from Pfizer/BioNTech and Moderna, which were around 95% 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.
The top U.S. infectious disease specialist Anthony Fauci said the variations in effectiveness around the world underlined the need to vaccinate as many people as quickly as possible to prevent new variants from emerging.
“It’s really a wake up call for us to be nimble and to be able to adjust as this virus will continue for certain to evolve,” Fauci said.
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 of 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. It has said it plans to deliver 1 billion doses in 2021 and will produce the vaccine in the United States, Europe, South Africa and India.
Public health officials are counting on the J&J vaccine to increase much-needed supply and simplify immunization in the United States, which has a deal to buy 100 million doses of J&J’s vaccine and an option for an additional 200 million.
J&J said the vaccine would be ready immediately upon emergency approval, but Stoffels declined to say how many doses.
“Right now, any protection and additional vaccine is great. The key is not only overall efficacy but specifically efficacy against severe disease, hospitalisation, and death,” Walid Gellad, a health policy associate professor at the University of Pittsburgh, said.