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AstraZeneca May Have Used Outdated Data in Vaccine Trial (Updated)

The British-Swedish pharmaceutical will now work with health officials in the U.S. to provide updated efficacy data.


Updated on 3/25 at 9:30 a.m.

UPDATE: On March 25, AstraZeneca released modified data. The company now says its vaccine is 76% effective against symptomatic cases, 3% short of its originally stated 79%. However, these latest data show an 85% success rate in preventing symptomatic cases in those 65 and older, a 5% increase from the originally stated 80%.

Contrary to earlier news that AstraZeneca's Covid vaccine is effective in the U.S., the country's federal health officials now say that the British-Swedish pharmaceutical company may have used "outdated information" in drawing a conclusion, ABC News reports. 

The Data and Safety Monitoring Board — a collective of experts that monitors the National Institute of Dental and Craniofacial Research branch of the U.S. National Institutes of Health (NIH) — has expressed concern that the U.K.-based pharmaceutical giant did not provide a full picture of its data. The company had announced on Monday that its vaccine protected adults of all ages, boasting a 79% efficacy rate against symptomatic cases.  

Related: Moderna Designed a Covid-19 Vaccine in Just Two Days Thanks to mRNA Technology

As previously reported, AstraZeneca had released partial results of late-stage testing on more than 32,000 adult U.S. participants. Results purportedly showed a 100% percent success rate in shielding against hospitalizations and Covid-related deaths. The company was set to apply for authorized FDA use of the vaccine in early April.

According to the Washington Post, Anthony S. Fauci, director of the NIH’s National Institute of Allergy and Infectious Diseases, has attempted to allay concerns in regards to the board's latest revelation, maintaining that AstraZeneca's shot "is very likely a good vaccine."

In response to the board's findings, AstraZeneca said it would "immediately engage" with health officials to provide the most updated efficacy data, the Post further adds. 

So far, the federal government has only green-lit the distribution of vaccines from Johnson & Johnson, Pfizer and Moderna. 

Justin Chan

Written By

Entrepreneur Staff

Justin Chan is a news writer at Previously, he was a trending news editor at Verizon Media, where he covered entrepreneurship, lifestyle, pop culture, and tech. He was also an assistant web editor at Architectural Record, where he wrote on architecture, travel, and design. Chan has additionally written for Forbes, Reader's Digest, Time Out New YorkHuffPost, Complex, and Mic. He is a 2013 graduate of Columbia Journalism School, where he studied magazine journalism. Follow him on Twitter at @jchan1109.