AstraZeneca is having difficulty compiling the data necessary for its COVID-19 vaccine's FDA approval application, sources familiar with the effort told The Wall Street Journal April 29.
In March, the drugmaker said it would submit the vaccine's application for FDA emergency use authorization by mid-April. However, one source told the Journal it could now take until mid-May.
The drugmaker must gather data on efficacy, safety and virus transmission from real-world vaccinations in the U.K., where the vaccine has been approved for about four months.
The U.S. has stockpiled about 60 million doses of AstraZeneca's vaccine. Those doses will soon be available for export, as the U.S. believes it has enough doses of vaccines already approved by the FDA.
Even though the U.S. may not administer AstraZeneca's vaccine, an FDA approval would boost global confidence in the shot, which could alleviate concerns some people have about rare but serious blood clotting incidents.
Experts expect the FDA's review of AstraZeneca's vaccine to be scrutinous, as the National Institute for Allergy and Infectious Diseases issued a statement criticizing AstraZeneca's vaccine data in late March.
Less than a day after the drugmaker said its vaccine was 79 percent effective at preventing symptomatic COVID-19, NAID's data and safety monitoring board expressed concern the announcement was based on outdated data. Two days later, AstraZeneca lowered its vaccine's efficacy against symptomatic COVID-19 from 79 percent to 76 percent and maintained that it is 100 percent effective in preventing severe disease and hospitalization.