US Health Officials Question Results of AstraZeneca Vaccine


Results of AstraZeneca’s main US trial of the COVID-19 vaccine, Issued by a press release Monday morning surpassed experts’ expectations. But less than a day later, US health officials questioned the results, which have not yet been fully published.

at Experience The company said that more than 32,000 volunteers, two-thirds of whom received the vaccine, had a 79% effectiveness in preventing symptoms of COVID-19. This was based on 141 cases of the disease that occurred via the vaccine and placebo arms in the trial. – The absence of severe disease that requires hospitalization among the people who received the vaccine. Compared to five in the placebo armNational Institute of Allergy and Infectious Diseases (NIAID) chief Anthony Fauci said during a White House press conference on Monday.

“The good news is also that there is similar efficacy across race and age,” Fauci said.

But Early Tuesday morning, NIAID issued a very unusual statement that casts some doubt on the company’s report on its findings. The company “may have included outdated information from that experience, which may have provided an incomplete view of the effectiveness data,” the statement said.

Late Monday, the Data Safety Watch, the independent panel of medical experts tasked with overseeing the US AstraZeneca’s trial, notified the NIAID and other health officials that they were “concerned” about the way the results were being presented, the statement said.

AstraZeneca responded Tuesday morning to the concerns raised by the Independent Panel of Experts. “Numbers Published Yesterday it was based on a pre-defined interim analysis with a discontinuation of data on February 17th, “the company wrote.” We have revised the preliminary evaluation of the initial analysis and the results are in line with the interim analysis. We are now in the process of completing the validation of the statistical analysis. “

The company promised to “communicate immediately” with the independent committee “to share our basic analysis with the latest efficacy data”, saying it would release the results within the next two days.

“As a member of the FDA advisory committee, I want to see all the data – all the data collected. Any experience with this.” Paul Offitt, a vaccine expert at Children’s Hospital of Philadelphia, who works on the FDA’s Vaccine Advisory Committee, said, Anything is related to the decision. ” “Because the most important thing we keep in mind with these vaccines is safety. Safety, safety and safety.”

Appearing on Good morning America On Tuesday, Fauci said DSMB wrote a “somewhat harsh note” to AstraZeneca, copying Fauci, saying they felt the data in the press release “might in fact be a bit misleading”.

“It’s really unfortunate that this is happening,” Fauci said. “This is really what she calls a non-coercive mistake, because the truth is, it’s very likely a very good vaccine.”

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

It’s a good vaccine, but this type of PR makes it a lot messier and more complicated. It is difficult for the audience to analyze what is happening. We just want a clear, straightforward process that is easy to explain, Natalie Dean, a biostatistician at the University of Florida told BuzzFeed News. “We don’t really have any details. But just the appearance of everything does not serve anyone.”

The NIAID statement angered many scholars.

“We’re in uncharted territory. DSMBs don’t usually do things like this.
And a federal agency is barred from issuing a statement that raises concerns
John Moore, a virologist at Weill Cornell Medical College in New York, told BuzzFeed News by email:

The US health officials ’statement is only the latest in a string of problems encountered in 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 indicated an effectiveness of up to 70% overall. But scientists criticized those experiments, which included a group of experimental subgroups with patients of different age groups, doses, and intervals between the two vaccine shots, making them The numbers are very difficult to interpret.

It also means that the Oxford team has not been able to collect enough data to answer a major question: Does the vaccine protect elderly people who are most vulnerable to COVID-19 from contracting the disease? This caused some countries, including Germany at first Delay in leave of the vaccine For use in older age groups.

The new experiment finally has enough data to answer that question, according to the company version. An analysis of the results among people aged 65 or over indicated 80% efficacy in preventing symptoms of COVID-19.

“These results reaffirm previous results observed in AZD1222 trials across the entire adult population, but it is exciting to see similar efficacy results in people over the age of 65 for the first time,” said Ann Halsey of the University of Rochester School of Medicine, who co-led Experience for AstraZeneca, in company statement.

Crucially, the new experiment, which is taking place in the United States and many other countries, is A. Much simpler design Of those run by the Oxford team, with only two experimental groups. The volunteers were given either two doses of the vaccine four weeks apart or two injections of saline solution as a placebo.

Moore, who was a prominent critic of the Oxford experiments, last week described the US experience of BuzzFeed News as a “tough protocol” that should produce results that are easy to evaluate.

The company has not yet released any statements other than the findings summarized in its press release, but said that the paper “will be submitted for publication in a peer-reviewed journal.” The results will also be presented as the cornerstone of AstraZeneca’s application to the FDA to obtain the vaccine authorized for emergency use in the United States.

“We are preparing to present these findings to the US Food and Drug Administration and for millions of doses to be rolled out across America should the vaccine be granted a US license for emergency use,” Maine Pangalos, AstraZeneca’s executive vice president of biopharmaceuticals, said in a statement Monday. .

These results indicate that the two-dose AstraZeneca vaccine is more effective in preventing COVID-19 than the single-shot vaccine manufactured by Johnson & Johnson. 66% effective In disease prevention in its main experience. Both appear to be less effective than the two vaccines made by Pfizer / BioNTech and Moderna, which exceed 90% efficacy. All four vaccines appear to provide very strong protection against severe COVID-19.

The results of the new trial come after a fear of the safety of the AstraZeneca vaccine last week, when several European countries temporarily withdrew the vaccine from use after Reports of rare but serious blood clots.

The European Medicines Agency then analyzed data from nearly 20 million people who had been given the vaccine, and found 18 cases. Thrombosis of the cerebral venous sinuses (CVST), which can prevent bleeding from the brain and cause hemorrhage, seven cases Disseminated intravascular coagulation (DIC), which causes clots in tiny blood vessels throughout the body. While the agency could not rule out a link with the vaccine, it said the benefits of the vaccine in preventing COVID-19 Far outweighs the risks Of these serious cases, but very rare, and it is recommended to resume vaccination.

AstraZeneca said it did not find the CVST cases at its trial. This was expected, given that the condition is very rare and only about 21,000 people were given the vaccine in the trial.

Even before Tuesday’s statement from US health officials, some experts were concerned that the vaccine’s turbulent history might make it less attractive to the American public than the alternatives already available.

“The US Food and Drug Administration must now make a decision,” Moore told BuzzFeed News on Monday, “but even if this vaccine is approved, it can be difficult to convince the public to take it.” “Perception can become reality in such situations, and public confidence may not be there now.”

last week , The Biden administration announced It will loan millions of pre-manufactured doses of AstraZeneca to Canada and Mexico, where it has already been approved.

Dan Fergano contributed to writing this story.

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