US health service questions the robustness of AstraZeneca’s COVID-19 vaccine study data

(Reuters) – AstraZeneca Plc may have provided an incomplete picture of the efficacy data of its COVID-19 vaccine from a large-scale US trial, a US health agency said on Tuesday in another setback for the shot.

The news comes just a day after interim data from the drug manufacturer showed above-average results from the trial and casts doubt on its plan to seek US emergency authorization for the vaccine in the coming weeks.

The vaccine developed with the University of Oxford was 79% effective in preventing symptomatic illnesses in a large study in the United States, Chile and Peru, and, crucially, did not pose an increased risk of blood clots, according to the data.

The Data Safety Monitoring Board (DSMB) has “expressed concern that AstraZeneca may have included outdated information from that study, which may have provided an incomplete picture of the efficacy data,” said the US National Institute of Allergy and Health. Infectious Diseases (NIAID) in a statement.

NIAID is headed by American infectious disease expert Anthony Fauci and is part of the National Institutes of Health.

“We urge the company to work with the DSMB to review its efficacy data and ensure that the most accurate, up-to-date efficacy data is disclosed as soon as possible,” he said.

AstraZeneca did not immediately respond to a request from Reuters for comment.

Authorization and guidelines for use of the vaccine in the United States will be established after in-depth review of the data by independent advisory committees, the statement said.

Hailed as a milestone in the fight against the COVID-19 pandemic when it emerged as a vaccine candidate last year, the AstraZeneca shot was haunted by doubts about its efficacy, dosing regimen and potential 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 latest study data, which has yet to be assessed by independent researchers, would lend credence to the UK shot after results from previous, separate late-stage studies raised questions about the robustness of the data.

Fauci, who also serves as chief medical adviser to US President Joe Biden, said Monday the US trial found no evidence of the rare blood clots.

The latest data was based on 141 infections among 32,449 participants.

The shot was also at the center of a growing conflict between Brussels and London over so-called vaccination nationalism after a series of setbacks in supply in Europe.