A health professional prepares to inject an AstraZeneca vaccine against coronavirus disease (COVID-19).
Eloisa Lopez
AstraZeneca published updated phase three trial data for its Covid-19 vaccine on Wednesday after asking questions about the accuracy surrounding a preliminary report from its US study earlier this week.
The company now says its vaccine is 76% effective at protecting against symptomatic cases of viruses. A release released on Monday reported a symptomatic efficacy of 79%. The updated report states that the injection is 100% effective against serious illness and hospitalization.
A number of US health officials in recent days have criticized the company for what some claimed was “cherry picking” in an effort to make the results look more favorable.
The National Institute of Allergy and Infectious Diseases revealed Tuesday that it had been informed that the UK-based company may have included information from its US results that provided an “incomplete picture of the efficacy data.”
AstraZeneca said the figures at the time were based on a “pre-specified interim analysis” and pledged to share updated analysis in the coming days.
Dr. Anthony Fauci, White House chief medical adviser and director of the NIAID, called the situation “unfortunate” and said AstraZeneca was likely to issue an amended statement.
“This is really what you call a casual mistake because the fact is that this is very likely a very good vaccine,” Fauci told ABC’s Robin Roberts on “Good Morning America” on Tuesday. “Things like this … really raise some doubt about the vaccines and perhaps add to the hesitation. It wasn’t necessary.”
The updated results include data collected from 190 symptomatic cases across more than 32,000 participants – an increase of approximately 50 symptomatic cases studied compared to the dataset released Monday.
The findings suggest that the vaccine is more effective in patients 65 years of age and older than previously thought, with a newly reported efficacy of 85% for that population, compared to a previously mentioned 80%.
AstraZeneca reiterated Wednesday that the vaccine is “well tolerated” by the participants and that no safety concerns have been identified.
AstraZeneca has faced a separate backlash in recent weeks due to reports of blood clotting in conjunction with its vaccine, which is already approved and in use in dozens of countries around the world. Several European countries have suspended use of the vaccine and then resumed it after independent safety reviews.
—CNBC’s Berkeley Lovelace Jr., Sam Meredith and Steve Kopack contributed to this report.