The company’s initial data release Monday was met hours later by a rare rebuke from the government’s Data and Safety Monitoring Board, an independent group overseeing vaccine makers’ trials.
The group questioned why AstraZeneca used “outdated information” from an interim analysis of trial data in mid-February, rather than more up-to-date results showing slightly reduced, but still strong, efficacy, according to a late-night statement from the National Institute of Allergy and Infectious Diseases.
“The issue that the DSMB had is straightforward and very simple: The DSMB had data that they know the company had. When they saw the press release, they said, ‘wait a minute — the data in the press release do not reflect the most recent data that we know you have,'” NIAID Director Anthony Fauci said at the time.
AstraZeneca defended itself by saying the latest data were still “consistent” with what it had shared. While overall effectiveness ebbed slight down, efficacy in people 65 years old and over jumped from 80 to 85 percent. The company maintained Wednesday that its vaccine is 100 percent effective at preventing severe disease and hospitalization, mirroring its earlier announcement.
The latest results still place AstraZeneca well above the Food and Drug Administration’s bar for authorizing a coronavirus vaccine — 50 percent efficacy — for both adults overall and the elderly in particular. But the confusion has triggered worries that the public will lose confidence in the shot even as AstraZeneca is poised to deliver tens of millions of doses to the U.S. government. The company has said it plans to seek emergency authorization for its vaccine from the Food and Drug Administration by mid-April.
The U.S. furor comes less than a week after the European Medicines Agency rushed to assure member countries that the vaccine is safe and effective amid unsubstantiated fears that it caused blood clots, leading 13 countries to suspend its use.