The US government on Saturday authorised Johnson & Johnson’s single-dose COVID-19 vaccine. It is the third vaccine authorised in the US, following ones from Pfizer/BioNTech and Moderna, both of which require two doses.
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 authorisation, noting the three vaccines had not been studied head-to-head.
“We feel that each of these vaccines will be effective, will prevent hospitalisation, deaths and should be used,” she said.
In J&J’s 44,000-person global trial, the vaccine was found to be 66 per cent effective at preventing moderate-to-severe COVID-19 four weeks after inoculation. It was 100 per cent effective in preventing hospitalisation and death due to the virus.
The J&J vaccine is also under review by the European Union, where deliveries are expected starting in April and would build on the region’s thin supplies of the Pfizer/BioNTech, Moderna and AstraZeneca shots.
In South Africa, regulators were awaiting the FDA decision as their government looks to deploy more J&J vaccine against a variant of the virus called B.1.351 that is able to evade some vaccine protection.
J&J’s vaccine is being rolled out there prior to official authorisation for about 500,000 healthcare workers in a bid to stem infections from the variant, which has swept across the country and spread globally, including to the US.
The vaccine is one of the few that has been tested in clinical trials against the variant and had a 64 per cent efficacy rate at preventing moderate-to-severe disease in South Africa.
J&J said that the company was developing a second-generation vaccine that would target the concerning South African variant, and it will be ready to start Phase I trials by this summer.
J&J’s vaccine uses a common cold virus known as adenovirus type 26 to introduce coronavirus proteins into cells in the body and trigger an immune response. J&J is testing a two-dose version of its vaccine, with results expected this summer.
(Edits by EP News Bureau)