(Adds chief investigator saying Phase 3 results before
By Kate Kelland
LONDON, Nov 19 (Reuters) - AstraZeneca and Oxford
University's potential COVID-19 vaccine produced a strong immune
response in older adults, data published on Thursday showed,
with researchers expecting to release late-stage trial results
The data, reported in part last month but published in full
in The Lancet medical journal on Thursday, suggest that those
aged over 70, who are at higher risk of serious illness and
death from COVID-19, could build robust immunity.
"The robust antibody and T-cell responses seen in older
people in our study are encouraging," said Maheshi Ramasamy, a
consultant and co-lead investigator at the Oxford Vaccine Group.
"We hope that this means our vaccine will help to protect
some of the most vulnerable people in society, but further
research will be needed before we can be sure."
Late-stage, or Phase III, trials are ongoing to confirm the
findings, researchers said, and to test whether the vaccine
protects against infection with SARS-CoV-2 in a broad range of
people, including people with underlying health conditions.
Results of those trials should definitely be known by
Christmas, the Oxford Vaccine Group's director Andrew Pollard
said, adding it was too early to know whether and how well the
vaccine works in preventing COVID-19 disease.
"We haven't quite got to that point yet. We're obviously not
going to rush that," he told BBC radio. "We're getting close,
and it's definitely going to be before Christmas, based on the
The Oxford-AstraZeneca COVID-19 vaccine candidate, called
AZD1222 or ChAdOx1 nCoV-19, had been among the front-runners in
global efforts to develop shots to protect against infection
with the novel coronavirus, or SARS-CoV-2.
But rival drugmakers Pfizer Inc, BioNTech
and Moderna Inc have in the past 10 days edged ahead,
releasing data from late-stage COVID-19 vaccine trials that
shows more than 90% efficacy.
Unlike the Pfizer-BioNTech and Moderna shots, both of which
use new technology known as messenger RNA (mRNA), AstraZeneca's
is a viral vector vaccine made from a weakened version of a
common cold virus found in chimpanzees.
The Phase II trial reported in The Lancet involved a total
of 560 healthy volunteers, with 160 aged 18-55 years, 160 aged
56-69 years, and 240 aged 70 or over.
Volunteers got two doses of the vaccine or a placebo, and no
serious side effects related to the AZD1222 vaccine were
reported, the researchers said.
AstraZeneca has signed several supply and
manufacturing deals with companies and governments around the
(Reporting by Kate Kelland; Additional reporting by Alistair
Smout; Editing by Matthew Lewis and Alexander Smith)