AstraZeneca’s U.S. coronavirus vaccine trial data may have been ‘outdated,’ ‘incomplete,’ NIH agency says

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LONDON – Oxford University and the pharmaceutical giant AstraZeneca may have only used partial data when the team announced the strong results from a U.S. trial of its coronavirus vaccine, the National Institute of Allergy and Infectious Diseases said Tuesday in a highly unusual advisory.

The agency, part of the National Institutes of Health, said that late Monday, it was notified by the Data and Safety Monitoring Board of its concerns “that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data.”

On Monday, Oxford and AstraZeneca announced via news releases and interviews that its 32,000-person clinical trials in the United States, Chile and Peru showed that its vaccine was 79% effective in protecting volunteers from symptomatic covid-19, the illness caused by the coronavirus – and that it was 100% effective against severe illness.

The 79% efficacy figure in the AstraZeneca trials was higher than earlier clinical trials run by Oxford in Britain, Brazil and South Africa for the same vaccine, which found the shots 62% effective. The vaccine has been approved for use in ongoing inoculation campaigns in Britain and Europe. Millions of people have gotten their first dose.

The Data and Safety Monitoring Board is an independent a committee of experts responsible for reviewing clinical trial data on an ongoing basis to ensure the safety of study subjects and validity and integrity of the data.

In its statement, the National Institute of Allergy and Infectious Diseases urged AstraZeneca to work with the independent monitors “to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”

In a brief statement, AstraZeneca said its efficacy results published on Monday “were based on a pre-specified interim analysis with a data cut-off of 17 February. We have reviewed the preliminary assessment of the primary analysis and the results were consistent with the interim analysis. We are now completing the validation of the statistical analysis.”

The pharmaceutical company said it would “immediately engage” with the independent data safety monitoring board to discuss the most up- to-date efficacy data. AstraZeneca promised a more detailed analysis within 48 hours.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told The Washington Post on Sunday, before new questions were raised by the monitors, “The data look good. The numbers don’t lie.”

After the monitors raised a yellow flag, Fauci said on Tuesday morning that it was “really what you call an unforced error because the fact is this is very likely a very good vaccine.”

Speaking on ABC’s “Good Morning America” Fauci said, “This kind of thing does, as you say, do nothing but really cast some doubt about the vaccines and maybe contribute to the hesitancy.”

AstraZeneca said Monday it would apply for emergency use authorization by the Food and Drug Administration in the coming weeks. The U.S. government has preordered 300 million doses of AstraZeneca vaccine, but with three others vaccines already approved – from Moderna, Pfizer and Johnson & Johnson – it is not clear what role the AstraZeneca shot will play in the United States.

Some researchers described the reaction by the U.S. scientists – and the public airing over the meaning of the AstraZeneca data – as highly unusual.

Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, told science reporters Tuesday that it is not unknown for the data monitoring board to disagree with investigators over the interpretation of trial results.

“It is usually done in private, so this is unprecedented in my opinion,” Evans said.

Others speculated it may be a technical issue that can resolved quickly.

AstraZeneca’s coronavirus vaccine was designed to be a cheap, easy-to-administer dose that would protect not just citizens of wealthy nations but also those in the most vulnerable countries.

But collaboration between Oxford researchers and one of the world’s biggest drug companies, has been plagued with missteps as other vaccine rollouts gain speed.

First, there was confusing basic science, then missed delivery targets. Last week, a confidence-sapping pause in Europe followed reports of rare blood clots among a handful of the vaccinated.

And now pushback from independent monitors over AstraZeneca’s interpretation – and claims – of effectiveness in the U.S. clinical trials.

The concerns raised by Data and Safety Monitoring Board did not mention any concerns it had that AstraZeneca had downplayed possible side effects.

The European Medicines Agency, which regulates drugs in the European Union, declared the vaccine safe and effective and said it was not linked to a rise in the overall risk of blood clots. But the EMA did not rule out a possible link to rare cases of clotting in the brain, known as cerebral venous sinus thrombosis.

While most European countries that paused the use of AstraZeneca’s vaccine last week have restarted their programs with additional warnings to patients about risk factors, Scandinavian nations have held back.

The Norwegian medical regulator said on Sunday that two more people among about 120,000 people in the country that had recently received the AstraZeneca vaccine had died, taking the total number to four. They were among six people hospitalized for unusual forms of blood clots after receiving the vaccine.

The medical regulator said it could not rule out that the cases were related to the vaccine. It said that the unusual pattern of side effects, which includes blood clots, bleeding and a low platelet count, had not been reported with other coronavirus vaccines in the country.