Federal health officials and an independent oversight board accused AstraZeneca of presenting the world with potentially misleading information about the effectiveness of the company’s Covid-19 vaccine, an extraordinary blow to the credibility of a company whose product has been seen as critical to the global fight against the pandemic.
In a two-page letter to AstraZeneca and federal authorities on Monday, an independent panel of medical experts that was helping oversee the vaccine’s clinical trial in the United States said the company had essentially cherry-picked data that was “most favorable for the study as opposed to the most recent and most complete.”
Only hours earlier, AstraZeneca had issued a news release trumpeting the effectiveness and safety of its vaccine, whose low price has made it the leading vehicle to inoculate people worldwide. The company said that based on its U.S. trial, the vaccine appeared to be 79 percent effective at preventing Covid-19.
But the independent oversight board said in its letter that the vaccine’s efficacy may have been between 69 percent and 74 percent. The letter reprimanded AstraZeneca for an overly rosy description of the trial data.
“Decisions like this are what erode public trust in the scientific process,” the board wrote.
The letter prompted the National Institute of Allergy and Infectious Diseases to issue a sharply worded statement shortly after midnight on Tuesday, making public the panel’s concerns.
The public airing of a conflict between a pharmaceutical company and a board overseeing a clinical trial is highly unusual. It is almost certain to trigger extra scrutiny of the vaccine by the Food and Drug Administration and other regulators if AstraZeneca seeks emergency authorization of its vaccine in the United States in the coming weeks, as expected.
“Any type of thing like this could unfortunately contribute to a lack of confidence in the process,” said Dr. Anthony S. Fauci, the nation’s leading infectious disease expert.
The dispute centered on how AstraZeneca was determining whether participants in the clinical trial had possible or actual cases of Covid-19, according to people familiar with the situation. The board twice pushed AstraZeneca representatives to take a more rigorous approach, telling them they had sufficient information to determine how many volunteers had the disease.
But AstraZeneca unveiled its interim results on Monday without the full analysis the board requested, possibly casting its vaccine in an overly favorable light.
AstraZeneca defended the data it released on Monday, which it said showed the vaccine was 79 percent effective at preventing Covid-19. The company said on Tuesday that the interim results appeared to be “consistent” with more recent data collected during the trial. AstraZeneca said it would immediately share its latest efficacy data with the monitoring board. The company said it would reissue fuller results within 48 hours.
The results that AstraZeneca announced on Monday were a badly needed dose of good news, especially because they came at a moment when concerns about the vaccine’s safety had led more than a dozen countries, mostly in Europe, to temporarily suspend the shot’s use over concerns about possible rare side effects. The results not only affirmed the vaccine’s safety, but also made the vaccine look more effective than it appeared in earlier trials.
But members of the independent monitoring board were surprised by the company’s announcement. “They got concerned and wrote a rather harsh note to them and with a copy to me, saying that in fact they felt that the data that was in the press release were somewhat outdated and might in fact be misleading a bit and wanted them to straighten it out,” said Dr. Fauci, who runs the National Institute of Allergy and Infectious Diseases, on ABC’s “Good Morning America.”
That prompted the overnight statement from the infectious-disease institute, which is part of the National Institutes of Health.
Companies sponsoring drug or vaccine trials typically wait for the monitoring board to review analyses and conclude that the study has yielded an answer before they announce trial results.
Company executives do not see the results of the study until the monitoring board reports their study data back to the company. The monitoring board ultimately conveyed the results of the study to AstraZeneca in a meeting over the weekend, leading to the company’s announcement Monday morning.
The monitoring board’s slow progress fueled concerns among federal officials that AstraZeneca may have been sitting on the data or that the monitoring board had concerns about the way the data it was reviewing had been presented.
An AstraZeneca spokeswoman, whom the company declined to name, said on Friday that it was “completely incorrect” that the trial data had formatting problems or had not been submitted to the monitoring board in a clean fashion.
“As is often the case,” the spokeswoman said, monitoring boards “can request new or clarifying analyses of data from the trial. This would enable them to ensure the robustness of their determinations.”
AstraZeneca’s relationship with the U.S. authorities has been fraught since last year, when senior health officials believed the company was not being forthright about the design of its clinical trials, its results and safety issues. That skepticism carried over to last week, when senior officials at a number of federal health agencies grew suspicious about why AstraZeneca had not announced data from its U.S. study.
That U.S. trial, which involved more than 32,000 participants, was the largest test of its kind for the shot. The results AstraZeneca released on Monday were from an interim look at the data after 141 Covid-19 cases had turned up among volunteers.