Results from a U.S. trial of AstraZeneca’s COVID-19 vaccine may have used “outdated information,” U.S. federal health officials said early Tuesday.
The Data and Safety Monitoring Board said in a statement that it was concerned that AstraZeneca may have provided an incomplete view of the efficacy data.
AstraZeneca reported Monday that its COVID-19 vaccine provided strong protection among adults of all ages in a long-anticipated U.S. study, a finding that could help rebuild public confidence in the shot around the world and move it a step closer to clearance in the U.S.
In the study of 30,000 people, the vaccine was 79% effective at preventing symptomatic cases of COVID-19 — including in older adults. There were no severe illnesses or hospitalizations among vaccinated volunteers, compared with five such cases in participants who received dummy shots — a small number, but consistent with findings from Britain and other countries that the vaccine protects against the worst of the disease.
AstraZeneca also said the study’s independent safety monitors found no serious side effects, including no increased risk of rare blood clots like those identified in Europe, a scare that led numerous countries to briefly suspend vaccinations last week.
The AstraZeneca vaccine is one of four shots to have been approved for emergency use in Canada. It has yet to be approved in the United States.
AstraZeneca plans to file an application with the FDA in the coming weeks, and the agency’s outside advisers will debate the evidence.
Following a thorough review, authorization and guidelines for use of the vaccine in the U.S. will be determined by the FDA and Centers for Disease Control and Prevention.