Johnson & Johnson's coronavirus vaccine is delivered as a single shot, while both Pfizer and Moderna's require two jabs.
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  • US regulators just released detailed data on Johnson & Johnson's coronavirus vaccine.
  • Its efficacy rate against the 501Y.V2 variant is higher than previously reported. 
  • South Africa became the first country to roll out the vaccine last Wednesday.
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Johnson & Johnson's single-dose coronavirus vaccine has a 64% efficacy rate at preventing the more contagious South African variant, according to new report posted online by the Food and Drug Administration in the US on Wednesday.

The new report, prepared by the company, found its efficacy rate against the 501Y.V2 variant is seven percentage points higher than an earlier report released by the company. Johnson & Johnson previously said that the vaccine offers 57% protection against moderate to severe Covid-19 infections in South Africa.

Vaccine efficacy against severe Covid cases was 73%, 14 days after vaccination, increasing to 82% at least 28 days after vaccination.

There were no deaths due to Covid among South African trial participants who received the J&J vaccine. More than 5,000 South Africans took part in the J&J vaccine trial, of which around half received a placebo vaccine.

"These results suggest that the vaccine is efficacious against mortality associated with Covid-19," the report found.

South Africa became the first country in the world to officially roll out the vaccine last Wednesday. 

Unlike the AstraZeneca vaccines, which South Africa first procured, the Johnson & Johnson vaccine has proved that it can work against South Africa's 501Y.V2 variant.

See also: SA is the first country to roll out Johnson & Johnson vaccine - what you need to know about the jab

The US Food and Drug Administration's review of the data found the shot to be effective and safe, and regulators said there were no identified safety issues that would prevent an emergency OK.  

J&J's vaccine is widely expected to become the third Covid-19 vaccine to reach the American public. The healthcare giant has said it will have nearly 4 million doses ready to ship upon emergency authorisation and is on track to deliver 100 million doses to the US by the end of June.

See also: J&J vaccine side effects - what you need to know

J&J has emphasised the vaccine was strongly protective against severe disease, a benefit that held true across age groups and geographies. 

Reporting by Andrew Dunn and Business Insider SA.

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