U.S. Health Officials Question AstraZeneca Vaccine Trial Results


Federal health officials said Tuesday that the encouraging results that AstraZeneca announced about its Covid-19 vaccine may have been based on outdated and incomplete information about the vaccine’s effectiveness, an extraordinary blow to the credibility of an already embattled vaccine.

In a statement released after midnight, the National Institute of Allergy and Infectious Diseases said that an independent panel of medical experts that has been helping to oversee AstraZeneca’s U.S. trial had “expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data.”

The exact nature of the institute’s concerns — and the effect they might have on how effective the vaccine appears to be — was unclear. But it is highly unusual for such a dust-up about the integrity of a clinical trial, especially one as high-profile as this, to be aired in public.

“This is really what you call an unforced error,” Dr. Anthony S. Fauci, the nation’s leading infectious-disease expert, said on Good Morning America on Tuesday morning. “Because the fact is: This is very likely a very good vaccine, and this kind of thing does, as you say, do nothing but really cast some doubt about the vaccines and maybe contributes to the hesitancy.”

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.

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.

The company had not disclosed until Tuesday how up-to-date those data were. That information is important, because sometimes a more current look at clinical trial results can present a different effectiveness and safety.

If the analysis was conducted on data from a month or two ago, it is possible that a more current look would present a different picture of the vaccine’s effectiveness and safety. The company has said it will provide the F.D.A. with a more comprehensive, recent set of data than what it disclosed on Monday. Although no clinical trial is large enough to rule out extremely rare side effects, AstraZeneca reported that its study turned up no serious safety issues.

The fresh data may have arrived too late to make much difference in the United States, where the vaccine is not yet authorized and is unlikely to become available before May. By then, federal officials predict, there will be enough vaccine doses for all of the nation’s adults from the three vaccines that have already been authorized: Pfizer-BioNTech, Moderna and Johnson & Johnson.

Even so, the better-than-expected results were seen as a heartening turn for AstraZeneca’s shot, whose low cost and simple storage requirements have made it a vital piece of the drive to vaccinate the world.

Many millions of people have received the AstraZeneca shot worldwide, including 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.

AstraZeneca said on Monday that it would continue to analyze the new data and prepare to apply in the coming weeks for emergency authorization in the United States. The vaccine has already been approved in more than 70 countries, but clearance from American regulators would bolster its global reputation.

The statement from the infectious disease institute comes after a series of miscues and communication blunders by AstraZeneca dating to last year that have eroded American officials’ trust in the company.

Last summer, at least some top F.D.A. officials learned only from news reports that AstraZeneca had paused its Phase ⅔ vaccine trial in Britain after a participant developed neurological symptoms. Then in September, after another participant in the British study fell ill with similar symptoms, AstraZeneca halted its trials globally but failed to promptly notify the U.S. authorities.

The U.S. study was ultimately paused for seven weeks last fall, in part because AstraZeneca was slow to provide the F.D.A. with evidence that the vaccine had not caused the neurological symptoms. Investigators ultimately concluded that the illnesses could not be linked to the vaccine. Still, the delay was a key reason that AstraZeneca fell so far behind the three other manufacturers whose vaccines have been granted emergency authorization in the United States.

Sheila Kaplan contributed reporting.



Source link Health

Be the first to comment

Leave a Reply

Your email address will not be published.


*