AstraZeneca updates vaccine efficacy to 76 percent

AstraZeneca updated its vaccine efficacy to 76 percent after it said earlier in the week the efficacy was at 79 percent.

The analysis of 76 percent efficacy comes as the vaccine is in phase three for its U.S. trials to receive emergency authorization.

After AstraZeneca reported on Monday that the efficacy was at 79 percent, federal officials said the company used outdated data in its determination.

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AstraZeneca admitted they used “pre-specified interim analysis with a data cut-off" from Feb. 17 in its calculation of 79 percent efficacy. 

"We have reviewed the preliminary assessment of the primary analysis and the results were consistent with the interim analysis," the company said on Tuesday. "We are now completing the validation of the statistical analysis."

The updated data also found the vaccine had 100 percent efficacy against critical disease or hospitalization and 85 percent efficacy against symptomatic coronavirus in those over the age of 65.

Trust in the AstraZeneca vaccine in Europe plummeted this week after some European countries suspended the vaccine over fear that it was causing blood clots in individuals. 

The U.S. has yet to authorize the AstraZeneca vaccine. Pfizer, Moderna and Johnson & Johnson are the only vaccines on the market. 

“The primary analysis is consistent with our previously released interim analysis, and confirms that our COVID-19 vaccine is highly effective in adults, including those aged 65 years and over. We look forward to filing our regulatory submission for Emergency Use Authorization in the US and preparing for the rollout of millions of doses across America,” said Mene Pangalos, executive vice president of biopharmaceuticals research and development, in the AstraZeneca statement.