Johnson and Johnson’s single-dose Covid-19 vaccine was 66 percent effective at preventing moderate and severe disease in a global study, the company said Friday.
The hotly anticipated findings are the first from a late-stage trial that enrolled 45,000 people across the world.
While the shot was 72 percent effective in the U.S. arm of the trial, it fell to just 57 percent in South Africa, where a highly transmissible variant predominates.
Overall, the company said the shot was 85 percent effective in preventing severe disease, and that protective effect increased over time.
The vaccine provided “complete protection against COVID-related hospitalization and death,” the company added.
Despite research finding J&J’s vaccine and others to be almost ineffective, Nigeria as most developing countries are still scrambling to receive their share.
In Afrca’s most populous nation with over 130,000 positive cases and nearly 1,600 fatalities, its government announced that it has secured an additional 41 million doses of vaccines to add to previously ordered 100,000.
But the news that J&J’s vaccine is less effective against the South African variant, known as B1.351, comes days after vaccine makers Moderna and Pfizer said their shots are less potent against the strain.
Health officials in South Carolina reported the first known U.S. cases of the variant on Thursday.
Johnson & Johnson said it plans to file for emergency use authorization in early February and expects to have “product available to ship” immediately following authorization.
The vaccine could provide a critical single-dose option to health officials trying to vaccinate hard-to-reach or hesitant populations against the virus.
It is one of only two single-dose options in late-stage U.S. trials, and can be stored in refrigerators rather than freezers.
