Federal health officials said early Tuesday that results from a U.S. trial of AstraZeneca’s Covid-19 vaccine may have relied on “outdated information” that “may have provided an incomplete view of the efficacy data,” casting doubt on an announcement on Monday that had been seen as good news for the British-Swedish company as well as the global vaccination drive.
In a highly unusual statement released after midnight, the National Institute of Allergy and Infectious Diseases said that the data and safety monitoring board, an independent panel of medical experts under the National Institutes of Health that has been helping to oversee AstraZeneca’s U.S. trial, had notified government agencies and AstraZeneca late Monday that it was “concerned” by information the company had released that morning.
The institute urged AstraZeneca to work with the monitoring board “to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”
AstraZeneca did not immediately return a request for comment early Tuesday.
In a news release on Monday announcing the results of the U.S. trial, the company said that the vaccine it developed with the University of Oxford was 79 percent effective against Covid-19, a higher figure than observed in previous trials, and completely prevented the worst outcomes from the disease. The long-anticipated results were seen as encouraging global confidence in the vaccine, which was shaken this month when more than a dozen countries, mostly in Europe, temporarily suspended the shot’s use over concerns about possible rare side effects. After conducting a review, Europe’s top drug regulator said last week that the shot was “safe and effective.”
more than 17 million in Britain and the European Union, almost all without serious side effects. In an effort to increase public confidence, many European political leaders have gotten the injections in recent days. The AstraZeneca vaccine has also been administered in the past week to leaders in South Korea, Taiwan and Thailand.