AstraZeneca U.S. trial data a confidence booster for COVID-19 shot
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[March 22, 2021]
By Josephine Mason and Ben Blanchard
LONDON/TAIPEI (Reuters) - AstraZeneca's
COVID-19 vaccine performed better than expected in a major late-stage
trial potentially paving the way for its emergency authorization in the
United States and bolstering confidence in the shot after numerous
setbacks in Europe.
The drugmaker said on Monday that trials in Chile, Peru and the United
States found the vaccine, developed in conjunction with Oxford
University, was 79% effective in preventing symptomatic COVID-19 and,
crucially, posed no increased risk of blood clots. It intends to request
U.S. emergency authorization in coming weeks.
More than a dozen European countries, including Germany and France, had
halted use of the AstraZeneca vaccine earlier this month after some
reports linked it to blood clots in a very small number of people. They
have since resumed inoculation after a regional regulator said it was
safe, but an opinion poll on Monday showed Europeans remained sceptical
over its safety.
Hailed as a milestone in the fight against the COVID-19 pandemic when it
first emerged as a vaccine contender last year, the AstraZeneca shot has
since been dogged by confusion over its efficacy, dosing regimen and
possible side-effects as well as supply setbacks in Europe, where the
company has been at the centre of a growing conflict between Brussels
and London over so-called 'vaccine nationalism'.
The latest data should help address some of those concerns, analysts
said. Based on more than 32,000 people, the trial was larger and elderly
volunteers featured more prominently than in previous trial results from
the UK which had prompted some European countries to initially hold back
using the AstraZeneca shot on older people.
"It is clear this vaccine has very good efficacy (remember that 60% was,
prior to any trials being started, regarded as a good target), and that
this efficacy does not show a notable decline at older ages," said
Stephen Evans, Professor of Pharmacoepidemiology at the London School of
Hygiene & Tropical Medicine
AstraZeneca shares were up over 1% in early London trading.
U.S. trials of rival vaccines from Pfizer and Moderna, which are already
being deployed in the United States, have showed efficacy rates of
around 95%.
But the AstraZeneca vaccine, which is already widely used outside the
United States, is seen as crucial to tackling the spread of COVID-19
across the globe because it is easier and cheaper to transport than
rival shots.
"I have just finished getting the (AstraZeneca) injection, there is no
pain at the injection site, and there is no soreness of the body,"
Taiwan Premier Su Tseng-chang told reporters as the island launched its
inoculation campaign on Monday.
British Prime Minister Boris Johnson received his first dose of the
AstraZeneca COVID-19 vaccine on Friday, saying he "did not feel a
thing."
And French President Emmanuel Macron has said he would take the
AstraZeneca vaccine if that's what was offered after previously being
quoted as saying the shot was "quasi-ineffective".
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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/File Photo
HEADWINDS
The AstraZeneca vaccine has already been granted a conditional
marketing authorisation or emergency use in more than 50 countries,
spanning four continents.
But it has yet to be approved in the United States, where President
Joe Biden is stepping up the federal response to the pandemic by
expanding testing, ramping up vaccinations and boosting production.
University of Oxford professor Sarah Gilbert told BBC radio that
work to prepare a submission for Emergency Use Authorization in the
United States will take a few weeks. A company spokesman said the
filing would likely be in the first half of April.
The American trial results have not yet been reviewed by independent
researchers.
If the AstraZeneca vaccine gets U.S. approval, it would be the
fourth after Pfizer, Moderna and Johnson & Johnson.
It uses a modified version of a chimpanzee common cold virus to
teach the human body to make proteins from the novel coronavirus to
generate an immune response and prevent infection.
Scepticism over the shot started last year when the British
drugmaker and Oxford University published data with different
efficacy readings due to a dosing measurement error. Later analysis
suggested the dosing interval rather than the amount of dose
administers was responsible for the difference.
Many Asian countries heavily rely on the AstraZeneca vaccine to end
the pandemic, as the shot is being used in inoculation programmes in
Australia, South Korea, the Philippines, Vietnam, Thailand, and
India.
Some states in India, which has the highest coronavirus caseload
after the United States and Brazil, are seeking to accelerate the
vaccination drive, as the country reported its most COVID-19 cases
and deaths in months on Monday.
As vaccine demand rises at home, top producer the Serum Institute of
India has delayed further shipments of the AstraZeneca shot to
Brazil, Britain, Morocco and Saudi Arabia..
In Europe, meanwhile, the European Union has threatened to block
exports of COVID-19 vaccines to Britain to safeguard scarce doses
for its own citizens, with Commission President Ursula Von der Leyen
saying the epidemiological situation was worsening.
(Additional reporting by Pushkala Aripaka and Muvija M in Bengaluru,
Ludwig Berger in Frankfurt, Krishna Das in New Delhi, Colin Packham
in Canberra, Stanley Widianto in Jakarta, Sangmi Cha in Seoul, Neil
Jerome Morales in Manila and Kate Kelland in London; Writing by
Miyoung Kim and Barbara Lewis; Editing by Ana Nicolaci da Costa and
Carmel Crimmins)
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