Johnson and Johnson says Covid vaccine 66% effective overall, less so against S African variant

Johnson and Johnson on Friday said its single-dose vaccine was 72 per cent effective in preventing COVID-19 in the United States. But an effective lower rate of 66 per cent was observed globally in the large trial conducted across three continents and against multiple variants.

In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 was 66 per cent in Latin America and just 57 per cent in South Africa, where a deadly variant of the novel coronavirus is circulating.

The company's main study goal was the prevention of moderate to severe COVID-19, and the vaccine was 85 per cent effective in stopping severe disease and preventing hospitalizsation across all geographies and against multiple variants 28 days after immunisation.

Meanwhile, public health officials have been counting on the J&J vaccine to increase much-needed supply and simplify the U.S. immunization campaign.

Unlike the Pfizer/BioNTech and Moderna vaccines, J&J's does not require a second shot weeks after the first or need to be kept frozen, making it a strong candidate for use in parts of the world with weak transportation infrastructure and insufficient cold storage facilities.

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. The Pfizer/BioNTech and Moderna vaccines use a new technology called messenger RNA (mRNA) that requires it to be stored in a freezer.

J&J has planned to deliver 1 billion doses in 2021 and will produce the vaccine in the United States, Europe, South Africa and India.