AstraZeneca says COVID-19 vaccine 76% effective in new analysis, to seek
U.S. approval
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[March 25, 2021]
By Rocky Swift and Swati Pandey
(Reuters) - AstraZeneca's said its COVID-19
vaccine was 76% effective in a new analysis of its U.S. trial - only a
tad lower than the level in an earlier report this week criticised for
using outdated data.
Interim data published on Monday had put the vaccine's efficacy rate at
79% but had not included more recent infections, leading to a highly
unusual public rebuke from U.S health officials.
The small revision to the efficacy rate will go a long way to putting
the vaccine back on track for gaining U.S. emergency use authorisation -
which it plans to seek in the coming weeks - and help AstraZeneca in its
efforts to dispel doubts about its effectiveness and side-effects,
independent experts said.
AstraZeneca also reiterated that the shot, developed with Oxford
University, was 100% effective against severe or critical forms of the
disease. There have been eight severe cases - all among trial
participants who received the placebo.
"The vaccine efficacy against severe disease, including death, puts the
AZ vaccine in the same ballpark as the other vaccines," said William
Schaffner, an infectious disease expert from the Vanderbilt University
School of Medicine, adding that he expects the shot to gain U.S.
approval.
The latest data was based on 190 infections among more than 32,400
participants in the United States, Chile and Peru. The earlier interim
data was based on 141 infections through Feb. 17.
It also said the vaccine showed 85% efficacy in adults 65 years and
older, higher than the 80% rate reported on Monday.
AstraZeneca said the latest data has been presented to the independent
trial oversight committee, the Data Safety Monitoring Board, and it
plans to submit the analysis for peer-reviewed publication in the coming
weeks.
"The primary analysis is consistent with our previously released interim
analysis, and confirms that our COVID-19 vaccine is highly effective in
adults," Mene Pangalos, executive vice president of BioPharmaceuticals
R&D at AstraZeneca said in a statement.
The drugmaker noted there were 14 additional possible or probable cases
to be analysed so numbers in later updates of the trial results may
fluctuate slightly.
The updated 76% efficacy rate compares with rates of about 95% for
vaccines from Pfizer/BioNTech and Moderna in their trial data.
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A vial labelled with the AstraZeneca coronavirus disease (COVID-19)
vaccine is seen in this illustration picture taken March 19, 2021.
REUTERS/Dado Ruvic/Illustration
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.
"This appears to be a very effective vaccine with no safety
concerns," said Paul Griffin, a professor at the University of
Queensland.
"Hopefully, this should now give people the confidence that this
vaccine is the right one to continue to use moving forward," he
said, adding that he and his parents have received the vaccine.
AstraZeneca's vaccine is seen as crucial in tackling the spread of
COVID-19 across the globe, not just due to limited supply of
vaccines but also because it is easier and cheaper to transport than
rival shots. It has been granted conditional marketing or emergency
use authorisation in more than 70 countries.
The vaccine, once hailed as a milestone in the fight against the
COVID-19 pandemic, has been dogged by questions since late last year
when the drugmaker and Oxford University published data from an
earlier trial with two different efficacy readings as a result of a
dosing error.
Then this month, more than a dozen countries temporarily suspended
giving out the vaccine after reports linked it to a rare blood
clotting disorder in a very small number of people.
The European Union's drug regulator said last week the vaccine was
clearly safe, but Europeans remain sceptical about its safety.
Canada on Wednesday said it was safe but added a warning to the
vaccine's label about rare blood clots.
Its rollout has also been marred by production glitches and export
curbs imposed by India and the European Union, threatening to slow
global efforts to end the pandemic which has killed more than 2.8
million.
(Reporting by Rocky Swift in Tokyo, Swati Pandey in Sydney, Peter
Henderson in San Francisco and Shubham Kalia in Bengaluru; Writing
by Miyoung Kim; Editing by Edwina Gibbs)
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