Results from AstraZeneca’s key US trial of COVID-19 vaccine, released by press release on Monday morning, exceeding experts’ expectations. But less than a day later, US health officials questioned the results that were not yet fully disclosed.
In one experiment The company said with the participation of more than 32,000 volunteers, about two-thirds of whom received the vaccine, the injections were 79 percent effective in preventing symptomatic COVID-19, the company said. said. This is based on 141 cases occurring across the vaccine and placebo groups of the trial. There were no serious illnesses requiring hospitalization among those vaccinated, compared with year in the placebo groupNational Institute of Allergy and Infectious Diseases (NIAID) Anthony Fauci said during a press conference at the White House on Monday.
“The good news is that there is a similar effect between ethnicities and ages,” said Fauci.
But early Tuesday morningThe NIAID issued a very unusual statement that caused some doubts about the company’s report of results. The company “may have included outdated information from that experiment,” the statement said, “possibly providing an incomplete view of the performance data.”
The statement said late on Monday, the Data Safety Surveillance Board, an independent panel of health professionals tasked with overseeing the AstraZeneca trial in the United States, notified the NIAID and officials. Other health care providers say they are “concerned” about how the results are presented.
On Tuesday morning, AstraZeneca responded to the concerns of an independent panel of experts. “The numbers published yesterday based on a pre-specified interim analysis with data cutoff on Feb. 17, ”the company wrote. “We have considered the preliminary evaluation of the primary analysis and the results are consistent with the interim analysis. We are currently completing validation of the statistical analysis ”.
The company promised to “join immediately” with an independent panel to “share our key analysis with the most up-to-date performance data,” saying it will deliver results within the next two days.
“As a member of the FDA advisory committee, I want to see all the data – all the data has been collected. Any experience with this. Anything has to do with the decision, said Paul Offit, a vaccine expert at Children’s Hospital Philadelphia who is on the FDA’s vaccine advisory committee. “Because the most important thing we consider with these vaccines is safety. Safe, safe, safe. “
Appears on Morning dawn to America On Tuesday, Fauci said that DSMB wrote a “pretty harsh note” to AstraZeneca, cloning Fauci, saying it felt the data in the press release “could actually be a bit misleading”.
“It’s unfortunate that this has happened,” said Fauci. “This is really what you call an imperceptible bug, because of the fact that this is most likely a very good vaccine.”
Other experts expressed similar concerns about how the company presented its data.
“It’s a good vaccine, but this kind of public relations tool makes it all a little messy and a little more complicated. It is even more difficult for the public to analyze what is happening. We just wanted a clear and simple process that was simple and easy to interpret, ”Natalie Dean, a biostatisticsist at the University of Florida, told BuzzFeed News. “We don’t really have any details. But just the appearance of all does not make anyone support. “
The statement from the NIAID caught many scientists off guard.
“We are in unexplored territory. DSMB usually doesn’t do things like this,
and bar for a federal agency to issue a statement raising concerns
John Moore, a virologist at Weill Cornell Medical College in New York, told BuzzFeed News by email.
Statements from US health officials are only the latest in the series of problems faced by the AstraZeneca COVID-19 vaccine trials.
Previous results from trials in the UK and Brazil – run by the University of Oxford, where the vaccine was developed – showed an overall effect of around 70%. But scientists have criticized those trials, including a series of subgroups that test patients of different ages, dose and interval between vaccines, causing it to It is very difficult to explain the numbers.
This also means that the Oxford team was unable to gather enough data to answer an important question: Does the vaccine protect the elderly most susceptible to COVID-19 from disease? That leaves several countries, including Germany, initially, delay the vaccine licensing for older age groups.
The new beta finally has enough data to answer this question, according to the company statement. Analysis of results in people 65 years of age and older showed 80% effectiveness in preventing symptomatic COVID-19.
“These findings confirm previous results observed in the AZD1222 trials in all adult populations but it was interesting to see similar results for the first time in people over 65 years of age,” Ann Halsey from the University of Rochester School of Medicine, who co-led the trial for AstraZeneca, said in the company’s statement.
Crucially, the new test, which runs in the US and several other countries, is one The design is much simpler compared with studies run by the Oxford team, with only two experimental groups. 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 prominent critic of Oxford-run trials, last week described the US experiment with BuzzFeed News as a “rigid process” that produces easy-to-evaluate findings. than.
The company has yet to release any data other than the results summarized in its press release but said an article “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 emergency approval in the United States.
“We are preparing to submit these findings to the US Food and Drug Administration and to roll out millions of doses across the US if the vaccine is under the US Emergency License,” Mene Pangalos, AstraZeneca’s Executive Vice President of Biopharmaceuticals, said in a statement on Monday. .
These results suggest that the two-dose vaccine of AstraZeneca is slightly more effective at preventing COVID-19 than the single-dose vaccine made by Johnson & Johnson. 66% effective in the prevention of epidemics in its large test. Both appear to be less effective than the biphasic vaccines produced by Pfizer / BioNTech and Moderna, which exceeded 90% of efficacy. All four vaccines seem to provide very strong protection against the serious COVID-19.
The new test results come after concerns about the safety of the AstraZeneca vaccine last week, when many European countries temporarily withdrawing the vaccine after Reports of blood clots are rare but serious.
The European Pharmaceutical Authority then analyzed data of nearly 20 million people who had been vaccinated, finding 18 cases. Cerebral venous sinus thrombosis (CVST), which can stop blood from flowing out of the brain and causing bleeding, and seven Intravascular scattered coagulation (DIC), causes blood clots in small blood vessels throughout the body. Although the agency was unable to rule out a link with the vaccine, it said that the benefit of the vaccine in preventing COVID-19 out of risk of these serious but very rare conditions, and continued vaccination is recommended.
AstraZeneca said it found no cases of CVST in its testing. This was to be expected, as the condition is rare and only about 21,000 people were vaccinated during the trial.
Even before Tuesday’s announcement from US health officials, some experts were concerned that the troubled history of vaccines could make the U.S. public less attractive than alternatives. that is available.
“The FDA has to make a decision,” Moore told BuzzFeed News on Monday, “but even with a vaccine approved, it can still be difficult to convince the public to use it.” “Consciousness can come true in situations like these, and public trust simply may not be there now.”
Last week, Biden management board announced that they will lend to Canada and Mexico millions of doses of the pre-made AstraZeneca vaccine to Canada and Mexico, which have been approved.
Dan Vergano contributed reports to this story.