The U.S. government on Saturday authorized Johnson & Johnson’s single-dose COVID-19 vaccine, enabling millions more Americans to be vaccinated in the coming weeks and setting the vaccine up for additional approvals around the world, Reuters reported.
The J&J vaccine is the third authorized in the United States, following ones from Pfizer/BioNTech and Moderna, both of which require two doses.
The U.S. Food and Drug Administration announced the emergency use authorization of the J&J vaccine for adults aged 18 and older following Friday’s unanimous endorsement by the agency’s panel of outside experts. Shipments to vaccination sites are expected to begin Sunday or Monday.
President Joe Biden hailed the move but cautioned Americans against celebrating too soon. “Things are still likely to get worse again as new variants spread,” he said in a statement, urging people to continue washing their hands, wearing masks, and maintaining social distancing.
“There is light at the end of the tunnel, but we cannot let our guard down now or assume that victory is inevitable,” he said.
Both the Pfizer and Moderna vaccines, which are based on new messenger RNA technology, showed higher efficacy rates in pivotal trials that used two doses versus J&J’s single-shot vaccine. Direct comparison, however, is difficult because the trials had different goals and J&J’s was conducted while more contagious new variants of the virus were circulating.
“We believe that people should take the vaccine they are able to access,” the FDA’s acting commissioner, Dr. Janet Woodcock, said in a call after the authorization, noting the three vaccines had not been studied head-to-head.
“We feel that each of these vaccines will be effective, will prevent hospitalization, deaths and should be used,” she said.
In J&J’s 44,000-person global trial, the vaccine was found to be 66% effective at preventing moderate-to-severe COVID-19 four weeks after inoculation. It was 100% effective in preventing hospitalization and death due to the virus.
There were very few serious side effects reported in the trial, which also offered preliminary evidence that the vaccine reduced asymptomatic infections.
More study is expected. The FDA on Saturday dismissed the idea that evidence proved the vaccine prevented transmission between people and added there was no data to determine how long the vaccine’s protection lasted.
J&J’s vaccine is expected to be used widely around the globe because it can be shipped and stored at normal refrigerator temperatures, making distribution easier than for the Pfizer/BioNTech SE and Moderna vaccines, which must be shipped frozen.
“It potentially could play a very substantial role if we have enough doses because it’s only a single-dose vaccine and that will make it attractive to people who are difficult to reach,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville. “It’s one and done.”