U.S. Health Officials Question AstraZeneca Vaccine Results


Results from AstraZeneca’s important US trial of the COVID-19 vaccine, issued in a press release on Monday morning, exceeded the expectations of experts. But less than a day later, U.S. health officials questioned the consequences, which have also yet to be fully released.

In a test involving more than 32,000 volunteers, about two-thirds of those who received the vaccine, the shots had a 79% effectiveness in preventing COVID-19 symptoms, according to the company. This was consistent with 141 cases of the disease occurring throughout the vaccine and placebo trial arms. There were no cases of serious illness requiring hospitalization in people given the vaccine, compared with five on the placebo button, National Institute of Allergy and Infectious Diseases (NIAID) chief Anthony Fauci spoke during a press conference at the White House on Monday.

“The good news is also that it has similar effectiveness across all ethnicities and ages,” Fauci said.

but early Tuesday morning, NIAID issued a more separate statement questioning the company’s report on its results. The company “may have included some information from the test,” the statement said, “which may provide an incomplete view of the effectiveness data.”

The statement said that on Monday, the Data Safety Monitoring Board, the independent panel of medical experts tasked with overseeing the U.S. trial of AstraZeneca, informed NIAID and other health officials that it was “concerned” by the way showing the results.

On Tuesday morning, AstraZeneca responded to concerns raised by an independent panel of experts. “The numbers published yesterday was based on a pre -scheduled interim analysis with a data cut on 17 February, ”the company wrote. “We reviewed the preliminary analysis in the primary analysis and the results were consistent with the interim analysis. We have now completed the validation of the statistical analysis.”

The company promised to “immediately partner” with the independent panel to “share our key analysis of the more recent effectiveness data,” saying it would provide internal results. over the next two days.

“As a member of the FDA’s advisory committee I want to see all the data – all the data collected. Any experience with it. Anything related to the decision,” said Paul Offit, an expert of vaccination at Children’s Hospital in Philadelphia, which sits on the FDA’s vaccine advisory committee. ”Because the most important thing we consider about vaccines is safety. Safe, safe, safe. “

Appeared on Good Morning America on Tuesday, Fauci said the DSMB wrote a “more serious letter” to AstraZeneca, copying Fauci, saying they felt the press release data was “actually a little misleading.”

“It’s really unfortunate that this happened,” Fauci said. “This is exactly what you call uncontrolled error, because the truth is it’s probably a very good vaccine.”

Other experts have expressed similar concerns about how the company presents its data.

“It’s a good vaccine, but it’s this kind of public relations that makes it all a bit more confusing and more complicated. It’s harder for the public to move on from what’s going on. We just want a clean straightforward process that is easy to interpret, ”Natalie Dean, a biostatistician at the University of Florida, told BuzzFeed News. We really don’t have the details. But just the looks of it all didn’t make anyone a favorite. ”

The statement from NIAID has caught the attention of many scientists.

“We are in uncharted territory. DSMBs don’t usually do things like this,
and the bar for the federal agency to issue a statement raising concerns
about a high -profile corporate trial is definitely very, high, ”John Moore, a virologist at Weill Cornell Medical College in New York, told BuzzFeed News via email.

The statement from U.S. health officials is the latest in a series of problems faced by AstraZeneca COVID-19 vaccine trials.

Earlier results from trials in the UK and Brazil – run by the University of Oxford, which developed the vaccine – showed almost 70% effectiveness overall. Although the scientists were critical of the trials, which included a series of experimental subgroups of patients with different ages, doses, and intervals between the two vaccine outbreaks, they did. very difficult to interpret the numbers.

It also means that the Oxford team did not gather enough data to answer an important question: Does the vaccine protect older people who are more vulnerable to COVID-19 from becoming ill? That’s why some countries, which originally included Germany, did that delay vaccination approval for use in older age groups.

The new test finally has enough data to answer this question, according to the company release. Analysis of outcomes among people aged 65 and older showed 80% effectiveness in preventing COVID-19 symptoms.

“These findings also reinforce previous results observed in AZD1222 trials in the entire adult population but it is gratifying to see similar recovery outcomes in people over 65 for the first time. , ”Ann Halsey of the University of Rochester School of Medicine, co -founder of The AstraZeneca, said in the company release.

Crucially, the new test, run in the U.S. and several other countries, is a much simpler scheme than the one run by the Oxford team, with only two experimental groups. Volunteers were given two doses of the vaccine four weeks apart or two saline injections as a placebo control.

Moore, who is a prominent critic of the tests run at Oxford, last week described the U.S. test of BuzzFeed News as a “strict protocol” that should make the findings more easily analyzed.

The company has not yet released any data beyond the results summarized in its press release but said a paper will be “submitted for publication in a peer -reviewed journal.” The results will also be submitted as the subject of AstraZeneca’s application to the FDA with vaccine approval for emergency use in the U.S.

“We are preparing to submit the findings to the U.S. Food and Drug Administration and for the launch of millions of doses across America if the vaccine is granted U.S. Emergency Use Authorization,” said Mene Pangalos, executive vice president of AstraZeneca for biopharmaceuticals, released on Monday. .

These results suggest that the AstraZeneca two-dose vaccine is more effective in inhibiting COVID-19 than a single-dose vaccine developed by Johnson & Johnson, which is 66% effective to prevent disease in its main test. Both seem to be less effective than the two -shot vaccine made by Pfizer / BioNTech and Moderna, which exceeded 90% effectiveness. All four vaccines appear to provide strong protection against severe COVID-19.

The new trial results came after a safety concern for the AstraZeneca vaccine last week, in which several European countries temporarily withdrew the vaccine from use afterwards. reports of rare but severe hemorrhage.

The European Medicines Agency immediately analyzed data for nearly 20 million people given the vaccine, finding 18 cases of cerebral venous sinus thrombosis (CVST), which prevents blood flow from the brain and causes hemorrhages, and seven cases of diffuse intravascular coagulation (DIC), which causes swelling of small blood vessels throughout the body. While the agency has not ruled out a link to the vaccine, it is said that the benefits of the vaccine to prevent COVID-19 more than risk in serious but rare conditions, and it is recommended to continue vaccination.

AstraZeneca said it found no cases of CVST in its trial. This is to be expected, as the condition is rare and nearly 21,000 people have been given the trial vaccine.

Even before Tuesday’s statement from U.S. health officials, some experts were concerned that the troubled history of the vaccine could make it less attractive to the U.S. public than the alternatives can be used.

“The FDA now has to make a decision, even if approving this vaccine can be difficult to persuade the public to get it,” Moore told BuzzFeed News on Monday. “The vision can be real in situations like this, and public confidence may not be there right now.”

Last week, the The Biden administration was notified to lend it millions of pre-source doses of the AstraZeneca vaccine in Canada and Mexico, where it has already been approved.

Dan Vergano provides reporting for this story.





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