By Kate Kelland
LONDON, Nov 19 (Reuters) - A potential COVID-19 vaccine
developed by AstraZeneca Plc and Oxford University
produced a strong immune response in older adults, giving hope
it may protect some of those most vulnerable to the disease,
data from mid-stage trials showed.
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 to the
pandemic disease, researchers said.
"The robust antibody and T-cell responses seen in older
people in our study are encouraging," said Maheshi Ramasamy, a
consultant and a co-lead investigator at the Oxford Vaccine
Group.
"The populations at greatest risk of serious COVID-19
disease include people with existing health conditions and older
adults. 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.
The first efficacy data from those Phase III trials is
"possible in the coming weeks", the Lancet report said.
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), the
AstraZeneca experimental shot is 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 world as it gets
close to reporting results of its late-stage trials.
(Reporting by Kate Kelland in London
Editing by Matthew Lewis)