In interviews with CNN, several vaccine advisers to the US government said that a lot of questions should be expected when and if AstraZeneca applies to the US Food and Drug Administration for emergency use authorization for its Covid-19 vaccine.
The advisers did not cast doubt as to whether AstraZeneca’s vaccine would ultimately gain emergency use authorization from the FDA. They did, however, say the company’s application will likely bring up issues that didn’t arise when the three Covid-19 vaccines currently used in the United States — made by Pfizer, Moderna and Johnson & Johnson — applied for their own emergency use authorizations.
“It’s clear more questions have been raised about the AstraZeneca vaccine than about any of the other vaccines which are now authorized in the US,” said Dr. Arnold Monto, acting chair of the FDA’s Vaccines and Related Biological Products Advisory Committee.
More than a dozen European countries have suspended their AstraZeneca vaccine rollouts over worries about blood clots, though many are now restarting the programs after the EU’s medicines regulator said it is safe to use on Thursday.
There have also been concerns about a mistake made in their clinical trial last year and efficacy data that raised questions. Also, South Africa has suspended use the vaccine because health authorities said it wasn’t effective enough against the variant identified there.
“This is the vaccine that’s had one glitch after another,” said Dr. William Schaffner, a liaison member of the CDC’s Advisory Committee on Immunization Practices.
As more and more European countries have suspended their AstraZeneca vaccine rollouts, the company, as well as international health agencies, have defended it.
“The safety of all is our first priority,” an AstraZeneca statement said Wednesday. “Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population.
The World Health Organization, UK health authorities and the European Medicines Agency have all voiced support for the AstraZeneca vaccine, saying its benefits outweigh any risks.
AstraZeneca expects to ask the FDA to authorize its Covid-19 vaccine for emergency use in March or early April, sources with knowledge of the company’s ongoing clinical trial told Reuters last week.