Results from AstraZeneca’s key trial in the United States of its COVID-19 vaccine, published by a press release On Monday morning, it exceeded the expectations of experts. But less than a day later, U.S. health officials have questioned the results, which have yet to be released at all.
In a process with more than 32,000 volunteers, about two-thirds of whom received the vaccine, the shots had a 79% effectiveness in preventing symptomatic COVID-19, the company said. This is based on the 141 cases of the disease occurring in the vaccines and in the placebo arms of the trial. There have been cases of serious illness requiring hospitalization among people who have been given the vaccine, compared to five in the placebo arm, Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID) said Monday during a White House press conference.
“The good news is also that there was comparable effectiveness between ethnicity and age,” Fauci said.
Ma first Tuesday morning, NIAID issued an extremely unusual statement raising some doubts about the company’s report of its results. The company “may have included obsolete information from that process,” the statement said, “which may have provided an incomplete view of the effectiveness data.”
The statement said that late Monday, the Data Security Monitoring Council, the independent panel of medical experts tasked with overseeing AstraZeneca’s U.S. trial, notified NIAID and other health officials that it was “concerned” by the way the results were presented.
Tuesday morning, AstraZeneca responded to concerns raised by the panel of independent experts. “The numbers published were based on a pre-specified interim analysis with a February 17 data cut-off, ”the company wrote.“ We reviewed the preliminary assessment of 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 engage” with the independent panel to “share our primary analysis with the latest effectiveness data,” saying it will issue results in the next two days.
“As a member of the FDA’s advisory committee, I want to see all the data – all the data that has been collected. Any experience with that. All that is relevant to the decision,” said Paul Offit, an expert on vaccination at the Philadelphia Children’s Hospital, which is part of the FDA’s vaccines advisory committee. “Because the most important thing we consider with these vaccines is safety. Safety, security, safety.”
Appears in Hello America on Tuesday, Fauci said the DSMB wrote a “rather harsh note” to AstraZeneca, copying Fauci, saying they heard the data in the press release “could actually be a bit misleading.”
“It’s really unfortunate that this situation has happened,” Fauci said. “That’s really what you call a non-forced error, because the fact is that this is very likely a very good vaccine.”
Other experts expressed similar concerns about how the company had presented its data.
“It’s a good vaccine, but this kind of public relations stuff makes everything a little messier and more complicated. It is more difficult for the public to analyze what is going on. We just want a clear process that is easy to interpret, “Natalie Dean, a biostatistician at the University of Florida, told BuzzFeed News.” We don’t really have any details. But just the appearance of it all doesn’t do anything to anyone. “
NIAID’s statement has taken many scientists off guard.
“We are in unknown territory. DSMBs don’t normally do things like that,
and the bar for a federal agency to issue a statement of concern
about a high-profile business process is certainly very, very high, ”John Moore, a virologist at Weill Cornell Medical College in New York, told BuzzFeed News by email.
The statement from U.S. health officials is just the latest in a series of problems that AstraZeneca COVID-19 vaccination trials have had.
Previous results from tests in the UK and Brazil – run by Oxford University, which developed the vaccine – had indicated about 70% effectiveness overall. But the scientists were critical of these trials, which had included a series of experimental subgroups with patients of different age groups, doses, and intervals between the two vaccine strokes, yielding very difficult to interpret the numbers.
This also meant that the Oxford team had not been able to gather enough data to answer a key question: Does vaccination protect older people who are more vulnerable to COVID-19 from patients? This caused some nations, initially Germany, to delay vaccine authorization for use in older age groups.
The new process finally has enough data to answer this question, according to the company’s publication. Analysis of the results among people 65 years and older indicated 80% efficacy in the prevention of symptomatic COVID-19.
“These findings confirm the previous results observed 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 co-led the process for AstraZeneca, said in the company’s release.
Crucially, the new process, managed in the United States and several other countries, is a much simpler conception of those managed 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 has been a prominent critic of the Oxford-run trials, last week described the U.S. trial to BuzzFeed News as a “rigid protocol” that should produce results that are easier to assess.
The company did not even publish data beyond 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 AstraZeneca application center to the FDA for having the vaccine authorized for emergency use in the United States.
“We are in preparation to send these findings to the American Food and Drug Administration and to develop millions of doses across America that vaccination is authorized for Emergency Use Authorization,” he said. said Mene Pangalos, AstraZeneca’s executive vice president for biopharmaceuticals, in a statement Monday.
These results suggest that AstraZeneca’s two-dose vaccine is slightly more effective at preventing COVID-19 than the single-shot vaccine made by Johnson & Johnson, which was 66% effective in the prevention of diseases in their major process. Both appear to be less effective than the two-shot vaccines made by Pfizer / BioNTech and Moderna, which exceeded 90% efficacy. All four vaccines appear to provide very strong protection against severe COVID-19.
The results of the new trials come after a safety outage for the AstraZeneca vaccine last week, when several European nations temporarily withdrew the vaccine from later use. reports of rare but serious blood clots.
The European Medicines Agency then analyzed data for nearly 20 million people who were given the vaccine, finding 18 cases of cerebral venous sinus thrombosis (CVST), which can prevent blood from the brain from causing bleeding, and seven cases of disseminated intravascular coagulation (DIC), which causes clots in small blood vessels throughout the body. While the agency has not been able to rule out a link to the vaccine, it said the benefits of the vaccine to prevent COVID-19 far outweighed the risk of these serious but very rare conditions, it is recommended to resume vaccination.
AstraZeneca said it did not find any case of CVST in its lawsuit. This was expected, since the condition is very rare and only about 21,000 people have been given the vaccine in the process.
Even before Tuesday’s statement by U.S. health officials, some experts were concerned that the vaccine’s troubled history might make it less appealing to the American public than the alternatives that are already available.
“The FDA has yet to make a decision, but even if this vaccine is approved it could be difficult to convince the public to take it,” Moore told BuzzFeed News on Monday. “Perception can become reality in situations like this, and public trust just can’t be there now.”
Last week, the The Biden administration has announced which would provide millions of prefabricated doses of the AstraZeneca vaccine in Canada and Mexico, where it has already been approved.
Dan Vergano contributed the signal for this story.