AstraZeneca's Covid-19 vaccine 76% effective in new analysis
WASHINGTON : AstraZeneca said its Covid-19 vaccine was 76 per cent effective in a new analysis of its US trial - slightly lower than the level in an earlier report this week criticised for using outdated data.
Data published on Monday had put the vaccine's efficacy rate at 79 per cent but had not included more recent infections, leading to a highly unusual public rebuke from US health officials.
The small revision to the efficacy rate will go a long way to putting the vaccine back on track for gaining US emergency use authorisation and help AstraZeneca dispel doubts about its effectiveness and side effects, independent experts said.
AstraZeneca also reiterated that the shot, developed with Oxford University, was 100 per cent effective against severe or critical forms of the disease.
There have been eight severe cases - all among trial participants who received the placebo.
EFFICACY
"The vaccine efficacy against severe disease, including death, puts the AZ vaccine in the same ballpark as other vaccines," said infectious disease expert William Schaffner from the Vanderbilt University School of Medicine. He expects the shot to gain US approval.
The latest data was based on 190 infections among more than 32,400 participants in the US, Chile and Peru. The earlier interim data was based on 141 infections through Feb 17.
AstraZeneca said the latest data has been presented to the independent trial oversight committee, and it plans to submit the analysis for peer-reviewed publication in the coming weeks.
The updated 76 per cent efficacy rate compares with rates of about 95 per cent for vaccines from Pfizer/BioNTech and Moderna in their trial data.
Experts have noted, however, that AstraZeneca's latest data is particularly significant because it was compiled after more infectious variants of the coronavirus became prevalent.
AstraZeneca's vaccine is easier and cheaper to transport than rival shots.- REUTERS
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