Johnson & Johnson, Novavax release vaccine efficacy results

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Johnson & Johnson’s single-shot novel coronavirus (COVID-19) vaccine candidate was 66 percent effective overall at preventing moderate to severe COVID-19, and 72 percent effective in the U.S., 28 days after vaccination, the company said in a press release earlier today.  

The company released data from its Phase 3 ENSEMBLE clinical trial, based on 43,783 participants accruing 468 symptomatic cases of COVID-19. The trial evaluated the efficacy and safety of the vaccine candidate in protecting moderate to severe COVID-19, with co-primary endpoints of 14 days and 28 days following vaccination. 

Among all participants from different geographies, including those infected with an emerging viral variant, the COVID-19 vaccine candidate was 66 percent effective overall in preventing moderate to severe COVID-19, 28 days after vaccination. The onset of protection was observed as early as day 14. The level of protection against moderate to severe COVID-19 infection was 72 percent in the United States, 66 percent in Latin America and 57 percent in South Africa, 28 days post-vaccination, officials said. The primary outcome did not count mild COVID-19 cases.

The news follows an announcement made yesterday by Novavax demonstrating 89.3 percent efficacy with its protein-based COVID-19 vaccine candidate in the United Kingdom. The study assessed efficacy during a period with high transmission and with a new UK variant strain of the virus emerging and circulating widely. The announcement also includes results from its Phase 2b study conducted in South Africa, with approximately 90 percent efficacy.

Vaccines already in distribution, Pfizer and BioNTech and Moderna, achieved efficacy rates close to 95 percent.

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