(Reuters) – AstraZeneca may have used “outdated information” in the results of a large-scale trial of the COVID-19 vaccine, a United States health agency said on Tuesday, casting new questions about the injection, its potential implementation in the United States and plunge its developers once again into controversy.
The highly unusual rebuke from federal health officials came just a day after provisional data from the pharmaceutical company showed better-than-expected results from the test in the United States, which was seen as a scientific counter-attack to the concerns that have haunted the shot since the end last year.
The vaccine developed with the partner Oxford University was 79% effective in preventing symptomatic diseases in the large trial that also occurred in Chile and Peru, according to the data. It was also 100% effective against severe or critical forms of the disease and hospitalization, and had no increased risk of blood clots.
The Data Safety Monitoring Board (DSMB), an independent committee that oversees the study, “expressed concern that AstraZeneca may have included outdated information from that study, which may have provided an incomplete view of the effectiveness data,” the National Institute of US Allergy and Infectious Diseases (NIAID) said in a bit.ly/3scE3ji statement released after midnight in the United States.
“We urge the company to work with the DSMB to review the effectiveness data and ensure that the most accurate and up-to-date effectiveness data is made public as soon as possible,” he said, adding that the DSMB informed AstraZeneca of its concerns.
AstraZeneca did not immediately respond to a request for comment from Reuters.
Its shares fell 1% in overnight trading.
NIAID is chaired by U.S. infectious disease specialist Anthony Fauci and is part of the National Institutes of Health. The DSMB is organized by NIAID, according to a document that describes the design of the trial. The council’s role is to provide study oversight and to evaluate clinical data to ensure the study’s safe and ethical conduct.
Authorization and guidelines for the use of the vaccine in the United States will be determined after a thorough analysis of the data by independent advisory committees, the statement added.
DOUBTS RAISED
Although hailed as a milestone in the fight against the COVID-19 pandemic when it emerged as a vaccine candidate last year, the AstraZeneca injection has seen a steady stream of questions raised about its effectiveness, dosage regimen and possible side effects.
More than a dozen European countries stopped using the vaccine earlier this month, after reports linked it to a rare blood clotting disorder in a very small number of people.
Germany and France resumed vaccines after the EU drug regulator said last week that it was safe, but an opinion poll on Monday showed that Europeans remained skeptical about its safety.
Fauci, who also serves as chief medical adviser to US President Joe Biden, said on Monday that the US test found no indication of the rare blood clots.
Before concerns about the blood clot, there were also separate separate studies at the end stage, conducted by partner Oxford University, which raised questions about their dosage regimen and the lack of data on its effectiveness for older people.
The most recent data, which has not yet been analyzed by independent researchers, was based on 141 infections among 32,449 participants.
Analysts also noted AstraZeneca’s achievement in producing robust test data against a backdrop of more infectious variant propagation in the United States and other countries.
The AstraZeneca vaccine, which is already widely used outside the United States, is seen as crucial to fighting the spread of COVID-19 around the world because it is easier and cheaper to transport than rival vaccines.
Conditional marketing or emergency use authorization has been granted in more than 70 countries. Many countries are relying heavily on it to end the pandemic, and several state leaders have taken the injection to boost confidence in the vaccine, including South Korea’s President Moon Jae-in, who received it on Tuesday.
The shot was also at the center of a growing conflict between Brussels and London over the so-called nationalism of the vaccine, after a series of setbacks in supply in Europe.
Reporting by Miyoung Kim in Singapore; Additional reporting by Shubham Kalia in Bengaluru and Ludwig Burger in Frankfurt; Editing by Edwina Gibbs and Josephine Mason