A federal agency hit the brakes on enthusiasm for AstraZeneca’s coronavirus vaccine, citing concerns about old and incomplete study data.
(CN) — In the latest blow to confidence in the AstraZeneca coronavirus vaccine, U.S. health officials said in a rare warning Tuesday that data released one day prior may have been “outdated,” giving an incomplete view of the vaccine’s efficacy.
AstraZeneca responded saying its newly released data included Covid-19 cases up to Feb. 17, as specified by its study rules, and that the company is still studying cases that occurred after that date. The company said it will have an update within two days.
Monday’s data had augured new confidence for the vaccine after safety concerns surrounding a small number of blood clots prompted several European countries to temporarily pause administering it.
In the new study data, AstraZeneca found no safety concerns, including increased risk of blood clots. It reported an overall 79% efficacy, with zero cases of serious illness or hospitalization. And the company included adults older than 65, filling in data gaps that had caused confusion about who should get the vaccine.
Not long after those results were made public, however, the Data and Safety Monitoring Board overseeing the clinical trials apparently raised concerns.
“The DSMB expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data,” the U.S. National Institute of Allergy and Infectious Diseases said in an unusual statement posted online early Tuesday.
“We urge the company to work with the DSMB to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible,” the agency added.
Responding to the officials’ announcement, AstraZeneca issued a statement later on Tuesday clarifying its data cutoff decision.
“The numbers published yesterday were based on a pre-specified interim analysis with a data cut-off of 17 February,” the company said, noting it is in the process of validating a statistical analysis of its remaining data.
“We will immediately engage with the independent data safety monitoring board (DSMB) to share our primary analysis with the most up to date efficacy data,” the statement continues. “We intend to issue results of the primary analysis within 48 hours.”
AstraZeneca said Monday that it plans to submit its data to the FDA for review “in the coming weeks.”
Regardless of whether the AstraZeneca vaccine becomes a fourth option in the United States, its global use is a key factor in curbing the pandemic, experts say. The vaccine designers have pitched it as a “vaccine for the world,” affordable and easily shipped at refrigeration levels, instead of having to be frozen.
Vaccine distribution across the globe will ultimately be the course to end the pandemic.
“Pandemics don’t end when one country gets vaccinated,” said Dr. Ashish Jha, dean of the Brown University School of Public Health. “We will continue to suffer, and face challenges as a country, if the rest of the world continues to have high levels of infection.”
Continued spread of the coronavirus internationally gives way to more opportunities for variants to arise, possibly including those resistant to vaccine.
“Given that we’re going to have plenty of vaccines,” Jha said of the United States, “we’ve really got to push on getting more vaccines out to the rest of the world.”