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Missteps could mar long-term credibility of AstraZeneca shot

In this Thursday, Feb. 25, 2021 file photo, a health worker holds a vial of the AstraZeneca vaccine to be administered to emergency services personnel during a mass COVID-19 vaccination campaign at Wanda Metropolitano stadium in Madrid, Spain. AstraZeneca's release of encouraging data about its coronavirus vaccine from its U.S. trial raised hopes that the drug company could bury doubts about the shot and put a troubled rollout behind it. But just hours later, U.S. officials released an unusual statement expressing concerns AstraZeneca had included "outdated information" from its study and that it may have provided "an incomplete view of the efficacy data." (AP Photo/Manu Fernandez, File)
In this Thursday, Feb. 25, 2021 file photo, a health worker holds a vial of the AstraZeneca vaccine to be administered to emergency services personnel during a mass COVID-19 vaccination campaign at Wanda Metropolitano stadium in Madrid, Spain. AstraZeneca's release of encouraging data about its coronavirus vaccine from its U.S. trial raised hopes that the drug company could bury doubts about the shot and put a troubled rollout behind it. But just hours later, U.S. officials released an unusual statement expressing concerns AstraZeneca had included "outdated information" from its study and that it may have provided "an incomplete view of the efficacy data." (AP Photo/Manu Fernandez, File) In this Thursday, Feb. 25, 2021 file photo, a health worker holds a vial of the AstraZeneca vaccine to be administered to emergency services personnel during a mass COVID-19 vaccination campaign at Wanda Metropolitano stadium in Madrid, Spain. AstraZeneca's release of encouraging data about its coronavirus vaccine from its U.S. trial raised hopes that the drug company could bury doubts about the shot and put a troubled rollout behind it. But just hours later, U.S. officials released an unusual statement expressing concerns AstraZeneca had included "outdated information" from its study and that it may have provided "an incomplete view of the efficacy data." (AP Photo/Manu Fernandez, File)

LONDON (AP) – AstraZeneca’s repeated missteps in reporting vaccine data coupled with a blood clot scare could do lasting damage to the credibility of a shot that is the linchpin in the global strategy to stop the coronavirus pandemic, potentially even undermining vaccine confidence more broadly, experts say.

The latest stumble for the vaccine came Tuesday, when American officials issued an unusual statement expressing concern that AstraZeneca had included “outdated information” when it reported encouraging results from a U.S. trial a day earlier. That may have provided “an incomplete view of the efficacy data,” according to the statement.

AstraZeneca responded that the results, which showed its shot was about 79% effective, included information through Feb. 17 but appeared to be consistent with more up-to-date data. It promised an update within 48 hours.

An independent panel that oversees the study scolded the company in a letter Monday for cherry-picking data, according to a senior administration official. The panel wrote to AstraZeneca and U.S. health leaders that it was concerned the company chose to use data that was outdated and potentially misleading instead of the most recent findings, according to the official, who discussed the contents on the condition of anonymity given the sensitivity of the matter.

“This will likely cause more vaccine hesitancy,” said Dr. Paul Hunter, a professor of medicine at the University of East Anglia.