U.K. Approves Covid-19 Vaccine Made by AstraZeneca, Oxford -- 4th Update
By Joseph Walker and Jenny Strasburg
LONDON -- The U.K. authorized a Covid-19 vaccine developed by
the University of Oxford and AstraZeneca PLC, opening the door for
the rollout of millions of doses in a country where infections have
surged amid a more infectious variant of the virus.
The green light represents the third emergency-use approval of a
Western-developed vaccine this month and comes as cases rise
sharply in the U.S. and Europe. A shot developed by Pfizer Inc. and
Germany's BioNTech SE and one by Moderna Inc. have both been
cleared in the U.S. and are being distributed there.
AstraZeneca's shot -- less effective in clinical trials than its
rivals' injections -- won't be available in the U.S. until the Food
and Drug Administration reviews large-scale trials still being
conducted there and decides to authorize its use.
The U.K. authorization comes as the country battles a new,
potentially more contagious variant of the coronavirus. The mutated
virus triggered travel bans recently on visitors and goods from
Britain, ratcheting up the political urgency for a speedy vaccine
rollout here. Pfizer's shot is already available in the U.K., where
Prime Minister Boris Johnson said on Dec. 21 that a half million of
the first of a two-dose regimen have been administered.
Scientists have said that the three Covid-19 vaccines authorized
by Western countries so far should be similarly effective against
the new British variant as they have been in clinical trials, a
view AstraZeneca executives share, according to a person familiar
with the matter. The new variant could be as much as 70% more
transmissible than more established forms of Covid-19, government
AstraZeneca and U.K. health officials said the two-dose regimen
is flexible in terms of when the second dose should be given,
anywhere from four weeks to 12 weeks after the first dose.
Delaying the second dose would help stretch supplies of the
vaccine so more Britons get a first shot sooner. But the vaccine's
full protection--benefits shown in clinical trials to prevent
hospitalization--only kicks in after the second dose.
Pfizer has promised the U.K. millions more doses by the end of
the year, but the AstraZeneca and Oxford shot -- made at facilities
in the country and elsewhere -- promises to quicken the rate of
inoculations by the country's state-run health-care system. The
National Health Service will determine which shot to provide people
depending on supply.
In clinical trials, the AstraZeneca vaccine proved to be
significantly less effective in preventing symptomatic Covid-19
than the vaccines by Pfizer and Moderna. But it still exceeded a
key hurdle of 50% efficacy set earlier this year by regulators
including the FDA, established as a benchmark for emergency
authorization to prevent hospitalizations and deaths.
AstraZeneca said Wednesday it will supply millions of doses in
the first quarter of next year, without specifying an exact number.
The U.K. has ordered up to 100 million doses of the vaccine, enough
for 50 million people.
The company said the vaccine will be used for adults 18 years
and older. It didn't provide any further guidance on the age of
recipients or dosing size.
The vaccine provided between 62% and 90% effectiveness against
symptomatic Covid-19, depending on dosage size. Two full doses
about a month apart led to the 62% reading, while a small subset of
trial volunteers who received a lower initial dose followed by a
second standard dose showed a 90% efficacy reading. That subset of
trial participants were all 55 years or younger. Oxford and
AstraZeneca scientists have said they are unsure why that regimen
would be more effective.
The partners previously said they were deferring to regulators
to analyze the combined clinical-trial results and recommend dosage
levels based on the data. The U.K.'s Medicines and Healthcare
products Regulatory Agency is expected soon to provide detailed
recommendations about the vaccine's use.
It is unclear how quickly other nations might authorize the
vaccine. A large clinical trial is under way in the U.S., where
AstraZeneca executives expect to have full trial data to submit to
U.S. regulators by February, according to a person familiar with
the matter. They have been submitting batches of data to European
regulators and are poised for potential authorization across the
European Union by February, the person said.
Oxford and AstraZeneca emerged early this year as front-runners
in the race to develop a Covid-19 vaccine before falling behind
competitors that were able to complete clinical trials faster.
Developed by scientists at Oxford's Jenner Institute, the vaccine
uses a weakened cold virus to courier genetic material from the
coronavirus into cells and trigger immunity with two shots spaced
one month apart.
AstraZeneca agreed in April to co-develop Oxford's technology
and distribute it around the world at no profit through the
pandemic. By November, the company had agreements to supply three
billion doses to every region in the world.
The partners have faced setbacks along the way to Wednesday's
milestone. In May, they launched a combined Phase 2 and 3 clinical
trial in the U.K. aimed at enrolling more than 10,000 volunteers
and obtaining initial results by August. But the study progressed
slower than hoped for initially, partly because of relatively low
infection rates in the U.K. for much of the summer and fall.
By the time AstraZeneca launched a planned Phase 3 U.S. study of
30,000 volunteers in late August, the company was trailing behind
rivals Pfizer and Moderna, which had begun similarly sized studies
a month earlier. Within two weeks, AstraZeneca paused all its
studies globally after a U.K. volunteer had an unexplained illness.
U.K. regulators allowed studies to resume quickly, but the U.S.
trial remained grounded for more than six weeks before U.S.
regulators lifted the hold in October.
Write to Joseph Walker at email@example.com and Jenny
Strasburg at firstname.lastname@example.org
(END) Dow Jones Newswires
December 30, 2020 04:11 ET (09:11 GMT)
Copyright (c) 2020 Dow Jones & Company, Inc.