Last checked at 
(Adds panel comments from Washington Post, researcher comment)
By Kate Kelland and Julie Steenhuysen
LONDON/CHICAGO, March 23 (Reuters) - AstraZeneca
will publish up-to-date results from its major U.S. COVID-19
vaccine trial within 48 hours after health officials publicly
criticized the drugmaker for using "outdated information" to
show how well the immunization worked.
The rare public rebuke marks the latest setback for the
vaccine once hailed as a milestone in the fight against the
COVID-19 pandemic but has since been dogged by questions over
its effectiveness and possible side effects.
AstraZeneca said results it published on Monday in which
the vaccine had demonstrated 79% efficacy were based on an
interim analysis of data through Feb. 17, and it would now
"immediately engage" with the independent panel monitoring the
trial to share its full analysis.
The British-based drugmaker on Tuesday said it had reviewed
the preliminary assessment of its full, or primary, analysis and
found it to be consistent with the interim report.
But the Washington Post reported that the data monitoring
panel told federal officials they had been working with the
company through March, had seen data that showed the vaccine
might be 69% to 74% effective, and had "strongly recommended"
AstraZeneca include that information in its public statement.
AstraZeneca shares fell 1.8% in London trading.
The U.S. National Institute for Allergy and Infectious
Diseases (NIAID) said on Monday that the board charged with
ensuring the trial's safety and accuracy had expressed concern
the company may have included outdated data that gave an
incomplete view of the shot's effectiveness.
NIAID Director Dr. Anthony Fauci called the whole issue a
really unfortunate unforced error.
"This is very likely a very good vaccine and this kind of
thing does ... nothing but really cast some doubt about the
vaccines and may contribute to the hesitancy," he told ABC's
"Good Morning America."
"The data really are quite good but when they put it into
the press release it wasn't completely accurate," he said.
In addition to the 79% efficacy in stopping symptomatic
illness in the trial conducted in the United States, Chile and
Peru, the data reported on Monday also showed the shot was 100%
effective against severe or critical forms of the disease and
posed no increased risk of blood clots.
Dr. Larry Corey, co-leader of the U.S. Coronavirus Vaccine
Prevention Network, which helped design AstraZeneca's U.S.
trial, said the monitoring panel's rebuke was something he had
not seen before. The virologist at Fred Hutchinson Cancer
Research Center in Seattle, praised the panel for speaking up,
saying it showed the system of checks and balances worked.
'NEGATIVE REPORTS'
The new doubts about the shot's efficacy coincide with its
rollout in dozens of countries and clouds the timeline for its
potential emergency use authorization in the United States.
"This is indeed an extraordinary act. The negative reports
about this vaccine do not stop, although my assessment is that
it is well tolerated and safe, but clearly less effective than
the two mRNA vaccines," said Peter Kremsner, from the University
Hospital in Tuebingen, Germany.
Vaccines from Pfizer/BioNTech and Moderna
that use messenger RNA (mRNA) technology to produce an
immune response both had efficacy rates of about 95% in their
pivotal clinical trials, far above the 50% benchmark set by
global regulators.
AstraZeneca's COVID-19 shot has faced 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.
Confidence in the vaccine took a further hit this month,
when more than a dozen countries, mostly in Europe, temporarily
suspended giving out the shot 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 an opinion poll on Monday showed
Europeans remained skeptical about its safety.
The latest trial data, which has yet to be reviewed by
independent researchers or regulators, was based on 141
infections among 32,449 participants.
Stephen Evans, a pharmacoepidemiology professor at London
School of Hygiene & Tropical Medicine, said the up-to-date data
request may have to do with efficacy readings from recent cases,
which may include new virus variants and thus lower protection
rates.
"The other vaccines may also show such reduced efficacy and
we don't know by how much," he said.
The AstraZeneca vaccine is seen as crucial in tackling the
spread of COVID-19 across the globe because it is easier and
cheaper to transport than rival shots.
It has been granted conditional marketing or emergency use
authorization in more than 70 countries.
Many countries are relying heavily on the shot to end the
pandemic, and several state leaders have taken it publicly to
boost confidence.
(Reporting by Miyoung Kim in Singapore, Shubham Kalia and
Pushkala Aripakain Bengaluru, Ludwig Burger in Frankfurt, Kate
Kelland in London and Julie Steenhuysen in Chicago; Writing by
Josephine Mason, Caroline Humer and Peter Henderson; Editing by
Edwina Gibbs, David Clarke and Bill Berkrot)
