(Reuters) – AstraZeneca Plc may have provided an incomplete view of the effectiveness data for its COVID-19 vaccine from a large-scale US trial, a U.S. health agency said on Tuesday in a new setback for the injection. .
The news comes just a day after provisional data from the drugmaker showed better-than-expected results from the trial and cast doubt on its plan to seek emergency US authorization for the vaccine in the coming weeks.
The vaccine developed with the University of Oxford was 79% effective in preventing symptomatic diseases in a large trial in the United States, Chile and Peru and, crucially, had no increased risk of blood clots, according to the data.
The Data Security Monitoring Council (DSMB) “expressed concern that AstraZeneca may have included outdated information from that study, which may have provided an incomplete view of the efficacy data,” said the National Institute of Allergy and Infectious Diseases of the United States. United States (NIAID) in a statement.
NIAID is chaired by U.S. infectious disease specialist Anthony Fauci and is part of the National Institutes of Health.
“We ask 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.
AstraZeneca did not immediately respond to a request for comment from Reuters.
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.
Acclaimed as a milestone in the fight against the COVID-19 pandemic when it emerged as a vaccine candidate last year, the AstraZeneca injection has been haunted by doubts about its effectiveness, dosage regimen and possible side effects.
More than a dozen European countries, including Germany and France, stopped using the vaccine earlier this month after reports linked it to a rare blood clotting disorder in a very small number of people.
The data from the latest tests, which have not yet been reviewed by independent researchers, has been set to give credit to the British shot, after the results of separate studies at the final stage raised questions about the robustness of the data.
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.
The most recent data were based on 141 infections among 32,449 participants.
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; Editing by Edwina Gibbs