US Health Officials Question AstraZeneca’s Vaccine Results

The results of AstraZeneca’s basic US test for the COVID-19 vaccine, which was released in a press release on Monday morning, exceeded experts’ expectations. However, less than a day later, US health officials questioned the results, which have not yet been fully released.

In a trial involving more than 32,000 volunteers, about two-thirds of whom received the vaccine, the shots were 79% effective in preventing symptomatic COVID-19, the company said. This was based on 141 cases of the disease that occurred in the vaccine vaccine and placebo. “There have been no cases of serious illness requiring treatment among those who received the vaccine, compared to five in the placebo category,” Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID), told a news conference on Monday.

“The good news is that there was also comparable effectiveness across ethnicities and ages,” Fauci said.

But early Tuesday morning, NIAID released an extremely unusual statement that casts doubt on the company’s report on its results. The company “may have included outdated information from this test,” the statement said, “which may have provided an incomplete picture of the performance data.”

The statement said that late Monday, the Data Security Monitoring Board, the independent team of medical experts overseeing the US AstraZeneca trial, informed NIAID and other health officials that it was “concerned” about the results.

On Tuesday morning, AstraZeneca responded to the concerns expressed by the independent panel of experts. “The figures released yesterday were based on a predetermined interim analysis with a data interruption of February 17,” the company wrote. “We have examined the preliminary evaluation of the primary analysis and the results were in accordance with the interim analysis. We are now completing the validation of the statistical analysis. “

The company promised to “get involved immediately” with the independent panel to “share our main analysis with the most up-to-date efficiency data”, saying it would release results within the next two days.

“As a member of the FDA Advisory Committee, I want to see all the data – all the data that has been collected. Any experience with it. “Anything to do with the decision,” said Paul Offit, a vaccine specialist at Philadelphia Children’s Hospital, who sits on the FDA’s vaccine advisory committee. “Because the most important thing we look at with these vaccines is safety. Security, security.

Appearing on Good Morning America on Tuesday, Fauci said the DSMB wrote a “rather harsh note” to AstraZeneca, copying Fauci, saying they felt the data in the press release “may actually be a little misleading”.

“It’s really unfortunate that this happened,” Fauci said. “This is what you call an unavoidable mistake, because the fact is that a very good vaccine is very likely.”

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

“It’s a good vaccine, but this kind of public relations makes it a little dirtier and more complicated. It is more difficult for the public to analyze what is happening. “We just want a clean and simple process that is easy to interpret,” Natalie Dean, a biostatist at the University of Florida, told BuzzFeed News. “We do not really have details. But only the appearance of all does no one any favors. “

The NIAID statement caught many scientists careless.

“We are in unknown territory. DSMBs usually do not do such things,
and the bar for a federal agency to issue a statement raising concerns
for a high-profile corporate test is definitely very, very high, “said John Moore, a virologist at Weill Cornell Medical College in New York, via email to BuzzFeed News.

The US health officials’ statement is the latest in a series of problems encountered by AstraZeneca COVID-19 vaccine trials.

Previous results from trials in the United Kingdom and Brazil – conducted by the University of Oxford, which developed the vaccine – have shown an overall effectiveness of around 70%. But the scientists were critical of these experiments, which included a series of experimental subgroups with patients of different age limits, doses and intervals between the two shots of the vaccine, making it very difficult to interpret the numbers.

It also meant that the Oxford team could not gather enough data to answer a key question: Does the vaccine protect older people who are more vulnerable to COVID-19 from getting sick? This has forced some nations, initially including Germany, to delay approving the vaccine for use in older age groups.

The new test finally has enough data to answer that question, according to the company announcement. The analysis of the results in people aged 65 years and over showed 80% effectiveness in the prevention of symptomatic COVID-19.

“These findings confirm previous results seen in AZD1222 trials in all adult populations, but it is exciting to see similar efficacy results in people over 65 for the first time,” said Ann Halsey of the University of Rochester School of Medicine. which led the test for AstraZeneca, the company said in a statement.

Basically, the new test, conducted in the US and many other countries, is a much simpler design than the one conducted by the Oxford team, with only two experimental teams. Volunteers were given two doses of the vaccine four weeks apart or two injections of saline as a placebo control.

Moore, who has been a vocal critic of the Oxford trials, last week described the US trial on BuzzFeed News as a “rigid protocol” that should make findings easier to evaluate.

The company has not yet released data beyond the results summarized in its press release, but said a document “will be submitted for publication in a peer-reviewed journal.” The results will also be submitted as the focus of AstraZeneca’s application to the FDA for approval of the emergency vaccine in the US.

“We are preparing to submit these findings to the US Food and Drug Administration and to dispense millions of doses across the United States if the vaccine is given to the United States for emergency use,” said Mene Pangalos, executive vice president of AstraZeneca Biopharmaceuticals. .

These results suggest that the AstraZeneca two-dose vaccine is slightly more effective in preventing COVID-19 than the shot vaccine developed by Johnson & Johnson, which was 66% effective in preventing the disease in its main trial. Both seem less effective than the two-vaccine vaccines developed by Pfizer / BioNTech and Moderna, which exceeded 90% efficacy. All four vaccines appear to provide very strong protection against severe COVID-19.

The new test results come amid fears of safety over the AstraZeneca vaccine last week, when several European nations temporarily withdrew the vaccine after reports of rare but severe blood clots.

The European Medicines Agency then analyzed data on nearly 20 million people who received the vaccine, found 18 cases of cerebral venous thrombosis (CVST), which can prevent blood from draining from the brain and cause bleeding, and seven cases. propagation of intravascular coagulation (DIC), which causes clots in tiny blood vessels throughout the body. While the agency could not rule out a link to the vaccine, it said the benefits of the vaccine in preventing COVID-19 far outweighed the risk of these serious but very rare conditions and recommended that the vaccine be repeated.

AstraZeneca said it did not find any CVST cases in its trial. This was to be expected, as the condition is very rare and only about 21,000 people received the vaccine in the trial.

Even before the announcement by U.S. health officials, some experts were concerned that the turbulent history of the vaccine might make it less appealing to the U.S. public than the alternatives already available.

“The FDA has to make a decision now, but even if this vaccine is approved, it would be difficult to persuade the public to get it,” Moore told BuzzFeed News on Monday. “Perception can come true in such situations and public confidence may not be there now.”

Last week, the Biden government announced it would lend millions of pre-made doses of the AstraZeneca vaccine to Canada and Mexico, where it has already been approved.

Dan Vergano contributed to this story.

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