Only hours after AstraZeneca announced encouraging news about the effectiveness of its Covid-19 vaccine on Monday, a group of medical experts charged with monitoring the company’s clinical trial made a highly unusual accusation: AstraZeneca had essentially cherry-picked data to make its vaccine look better.
The accusation, in a two-page letter sent Monday to the company and federal officials, was a fresh blow to the credibility of a vaccine whose low price and relatively easy storage have made it critical to the global fight against the pandemic.
The private letter, which was described by people who have read it, castigated AstraZeneca for jeopardizing the integrity of a closely watched clinical trial.
“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 fight is about the degree of effectiveness of a vaccine that is undisputably effective.
While AstraZeneca said on Monday that its vaccine appeared to be 79 percent effective at preventing Covid-19, the panel of independent experts said the actual number may have been between 69 percent and 74 percent. The mass availability of a vaccine with even a 69 percent efficacy rate could help the world conquer the coronavirus.
But the public airing of a conflict between a pharmaceutical company and a board overseeing a clinical trial is almost unheard-of. It is certain to trigger extra scrutiny of the vaccine by the Food and Drug Administration and other regulators if, as expected, AstraZeneca seeks their authorization to use it on an emergency basis in the United States.
Repeated problems with the data presented by AstraZeneca have shattered the confidence of American regulators and threaten to cast a worldwide cloud over the company’s vaccine.
“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.
Fears that the vaccine might trigger rare but serious side effects had led more than a dozen countries, mostly in Europe, to temporarily suspend the use of the shot. European regulators last week affirmed the vaccine’s safety. The results from the U.S. trial on Monday seemed to validate the vaccine’s safety and made it look more effective than in earlier trials.
In short, it bolstered the credibility of arguably the world’s most important vaccine, one that has been authorized for use in more than 70 countries. But the overnight announcement from the institute immediately raised a new set of questions about it and AstraZeneca.
But the overnight announcement from the institute immediately raised a new set of questions about it and AstraZeneca.
At issue is whether to count, in the public release of data, more recently confirmed cases of Covid-19 among participants. The oversight board pushed AstraZeneca representatives last week to go through a backlog of potential cases and classify whether they were or were not Covid-19. That had the potential to affect the vaccine’s effectiveness rate, for better or worse.
The requested analysis showed that the vaccine was between 69 percent and 74 percent effective, according to the oversight board’s letter.
But when AstraZeneca unveiled its interim results on Monday, the company did not count those newly classified Covid-19 cases. As a result, it reported that the vaccine appeared to be 79 percent effective at preventing the disease.
Until they received the monitoring board’s letter, AstraZeneca executives weren’t aware that the panel expected them to include the updated figures in their news release, according to a person familiar with the executives’ thinking.
Federal officials, however, were stunned to discover on Monday that AstraZeneca had released those results even though the monitoring board had spent days pushing for — and eventually received — updated data. By then, Dr. Fauci had publicly hailed the results at a White House briefing, and the company had been showered with positive media coverage. AstraZeneca’s shares rose about 4 percent on Monday.
AstraZeneca on Tuesday defended its actions, saying the interim results appeared to be “consistent” with more recent data collected during the trial. The company said it would immediately share its latest data with the monitoring board and reissue fuller results within 48 hours. The company’s shares fell 3.5 percent on Tuesday.
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.
Last week, an apparent delay in the release of the vaccine’s interim trial results raised fresh suspicions among federal officials.
In response to questions from The New York Times, an AstraZeneca spokeswoman, whom the company refused to name, said on Friday that any back and forth between the company and the monitoring board was simply run-of-the-mill dialogue.
“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.”
The 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.