(Adds comment, detail from news briefing)
* New trial data still shows lower efficacy than rival
vaccines
* Asia relying heavily on AstraZeneca to tackle pandemic
* Submission for U.S. approval could take few weeks
By Josephine Mason, Ben Blanchard and Ludwig Burger
LONDON/TAIPEI, March 22 (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 interim data from 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 the coming weeks.
More than a dozen European countries, including Germany and
France, had halted use of the AstraZeneca vaccine earlier this
month after 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 doubts 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 has yet to be reviewed by independent
researchers, but it helps to address some of the concerns,
analysts said.
"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," Stephen Evans, Professor of
Pharmacoepidemiology at the London School of Hygiene & Tropical
Medicine, said.
Based on more than 32,000 people, the trial was larger and
around 20% of volunteers were aged 65 and above, compared to
5.7% in an earlier British trial. The scarcer data had made some
European countries hesitant to use the AstraZeneca shot on older
people.
"Seeing this data now I hope gives others increased
confidence that this is a very effective and safe vaccine," Mene
Pangalos, an AstraZeneca executive vice-president, told a news
briefing.
AstraZeneca shares were up 2.6% in London, their highest
since Feb. 19.
U.S. trials of rival vaccines from Pfizer and
Moderna, which are 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.
Political leaders have come forward for the vaccine to try
to boost confidence.
"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".
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.
If the AstraZeneca vaccine gets U.S. approval, it would be
the fourth after Pfizer, Moderna and Johnson & Johnson.
Some analysts have said the United States might use its
AstraZeneca stockpile to largely support other countries rather
than for domestic use.
But Ruud Dobber, a AstraZeneca executive vice president,
said on Monday he would be "very surprised" if the company's
vaccine were not used in the United States.
The AstraZeneca shot 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.
Many Asia-Pacific 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.
.
AstraZeneca has set a target to produce 3 billion doses this
year, with India's Serum Institute making most of that aimed at
poorer nations.
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.
(Reporting by Ludwig Burger in Frankfurt. Additional reporting
by Pushkala Aripaka and Muvija M in Bengaluru, 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)