AstraZeneca insists its COVID-19 vaccine is very effective even after counting additional illnesses in its U.S. study, the latest in an extraordinary public dispute with U.S. officials.
In a press release on Wednesday night, the pharmacist said he had analyzed more data from this study and concluded that the vaccine is 76% effective in preventing symptomatic COVID-19, instead of the 79% it had. reported earlier in the week.
Just a day earlier, an independent group overseeing the study had accused AstraZeneca of cherry picking data promote the protection offered by your vaccine. The group, in a harsh letter to the company and U.S. health leaders, said the company had set aside some COVID-19 cases that occurred in the study, a move that could erode confidence in science.
Some experts said the new data provided by AstraZeneca was “reassuring” and that the information is likely to be solid enough for U.S. regulators to authorize the vaccine.
“It is possible that AstraZeneca was too hasty in submitting the previous and incomplete interim analysis instead of waiting to analyze and submit the complete dataset,” said Julian Tang, an offline University of Leicester virologist with research. He said the updated details did not look substantially different from what was released earlier this week.
Data disputes during ongoing studies are usually confidential, but in an unusual move, the National Institutes of Health publicly asked AstraZeneca to resolve the discrepancy.
AstraZeneca had the findings of a predominantly American study of 32,000 people to help rebuild confidence in a vaccine that, despite being widely used in Britain, Europe and other countries, has had a problematic deployment. Previous studies have revealed inconsistent data on its effectiveness, and last week a fright from blood clots caused some countries to temporarily pause inoculations.
Most have been restarted after the European Medicines Agency said the vaccine does not increase the overall incidence of blood clots., although he did not rule out the connection with some rare clots. On Thursday, Denmark announced that it would continue suspending the vaccine, with officials saying they needed more information before making a decision.
The question now is whether the company’s latest calculations can end the tension in the United States. Even before the latest dispute, experts had expressed concern that erroneous steps in vaccine launching could undermine confidence in the shot., which is crucial for global efforts to end the coronavirus pandemic, as it is cheap, easy to store and is a pillar of the COVAX initiative aimed at bringing vaccines to low- and middle-income countries.
Earlier Wednesday, Dr. Anthony Fauci, the top U.S. infectious disease expert, told reporters he hoped that when all data was publicly examined by federal regulators, it would dispel any hesitation caused by the spit. He predicted that “it would be a good vaccine.”
AstraZeneca’s most recent calculations were based on 190 cases of COVID-19 that occurred during the study, 49 more than it had included earlier in the week. The vaccine appears especially protective against the worst outcomes, with no serious illnesses or hospitalizations among vaccinated study volunteers compared to eight serious cases among those who received fake shots, the company said. It did not provide a breakdown of the remaining cases.
Some European authorities have questioned the protection of the vaccine in older adults. In the U.S. study, it was 85% effective in volunteers age 65 and older, the company said. The study did not report safety issues.
The updated information “confirms that our COVID-19 vaccine is highly effective in adults, including those over 65,” said Mene Pangalos, head of research at AstraZeneca. He said the company looks forward to “releasing millions of doses across America.”
The study is not complete, so additional cases of COVID-19 may still accumulate. AstraZeneca warned that 14 possible additional cases are already being examined and could lead to further changes in the data.
The company intends to seek authorization for the vaccine from the Food and Drug Administration within a few weeks. The FDA will publicly discuss all evidence with its external advisors before making a decision.
Stephen Evans, a vaccine expert at the London School of Hygiene and Tropical Medicine, said it was difficult to understand why the dispute between AstraZeneca and U.S. officials spread to the public.
“Given the details given here, it seems an unnecessary action to have raised concerns in public,” he said. “Results fluctuate as data accumulates … what will count will be the FDA assessment and will be done based on the review of the complete data and not the press releases.” He said any vaccine with an effectiveness rate of over 60% is helpful.
He said it was unclear why there was a “severance of relations” between AstraZeneca and independent U.S. data experts overseeing the trial and worried it could undermine confidence in the vaccine.
“This vaccine is so important to global health and disputes do not promote global health,” he said. “At least in the short term (this) will undermine confidence in both the US and, above all, the rest of the world.”
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Associated Press medical writer Maria Cheng in London and Jan M. Olsen in Copenhagen contributed to this report.
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The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.