Johnson & Johnson's Janssen coronavirus disease (COVID-19) vaccine - iHeart Radio
The United States on Saturday (Feb 27) authorised Johnson & Johnson's COVID-19 vaccine for emergency use, giving the nation a third shot to battle the outbreak that has killed more than 500,000 Americans.
The single-shot vaccine is highly effective in preventing severe COVID-19, including against newer variants, the Food and Drug Administration (FDA) said before approving it.
The FDA announced the emergency use authorisation for adults aged 18 and older following Friday's unanimous endorsement by the agency's panel of outside experts.
In large clinical trials, the vaccine's efficacy against severe disease was 85.9 per cent in the United States, 81.7 per cent in South Africa, and 87.6 per cent in Brazil.
Overall, among 39,321 participants across all regions, the efficacy against severe COVID-19 was 85.4 per cent, but it fell to 66.1 per cent when including moderate forms of the disease.
US President Joe Biden hailed the "exciting" announcement but warned the nation could not let its guard down.
"But we cannot let our guard down now or assume that victory is inevitable."
J&J expects to produce at least a billion doses of its vaccine in 2021 and has signed supply deals for most of that.
The United States agreed to pay more than US$1 billion for 100 million doses and may purchase an additional 200 million doses//CNA