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 The following is what we know about the race to deliver vaccines to
help end the coronavirus pandemic that has killed more than 1.7
million people worldwide:
WHO IS FURTHEST ALONG?
U.S. drugmaker Pfizer and German partner BioNTech are the COVID-19
vaccine trailblazers.
On Nov. 18, they became the first in the world to release full
late-stage trial data. Britain was the first to approve the shot for
emergency use on Dec. 3, followed by Canada on Dec. 9 and the U.S.
Food and Drug Administration (FDA) on Dec. 11. Several other
countries including Saudi Arabia and Mexico have also approved it.
The European Medicines Agency (EMA) approved the shot on Dec. 21 and
India is accelerating its review.
The World Health Organization could decide whether to give its
emergency use approval for the Pfizer candidate by the end of the
year as part of its COVAX programme aimed at providing shots for
poor- and middle-income countries.
WHAT ABOUT MODERNA?
Moderna Inc came a close second to Pfizer in many countries after it
released a full data analysis for a late-stage trial on Nov. 30
showing a 94.1% efficacy rate for its vaccine.
The United States authorised Moderna's vaccine on Dec. 19 while
Canada approved the shot on Dec. 23 and the EMA will do so on Jan.
6.
THE UK NOD FOR ASTRAZENECA
The UK's approval for AstraZeneca's vaccine is a major win for a
shot seen as crucial for mass immunisations even as questions have
swirled about the robustness of its trial data.
The British company announced interim late-stage trial data on Nov.
23 showing a half-dose followed by a full dose had a 90% success
rate while two full doses were 62% effective. The more successful
outcome, however, emerged in a much smaller number of participants,
and AstraZeneca is conducting more testing to see if that success
rate holds up in a wider population of volunteers.
The questions over the most effective dosing pattern have
complicated the approval process. While India is conducting an
accelerated review, it has asked for more data. AstraZeneca is also
in discussions with the EMA, which is conducting a rolling review of
the vaccine.
India is expected to make a decision on whether to approve for the
two full-dose regimen of the shot soon. Its review does not include
the more effective dosage.
WHO ELSE IS IN THE RUNNING?
U.S. drugmaker Johnson & Johnson plans to deliver trial data in
January 2021, teeing it up for U.S. authorization in February if its
shot is effective. It reduced the enrolment target for its clinical
trial to 40,000 volunteers from 60,000 on Dec. 9, potentially
speeding results which are tied to how quickly participants become
infected.
U.S. firm Novavax is running a late-stage trial in Britain with data
due in the first quarter of 2021. It expects to start a large-scale
trial in the United States this month.
France's Sanofi and Britain's GlaxoSmithKline, however, announced a
setback on Dec. 11 in their attempts to develop a vaccine. The
drugmakers said it showed an insufficient immune response in older
people in mid-stage trials and that they would start a new study in
February.
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WHAT HAPPENS IN THE TRIALS?
The companies typically test their vaccines against a placebo -
typically saline solution - in healthy volunteers to see if the rate
of COVID-19 infection among those who got the vaccine is
significantly lower than in those who received the dummy shot.
HOW ARE VOLUNTEERS INFECTED?
The trials rely on subjects becoming naturally infected with
COVID-19, so how long it takes to generate results largely depends
on how pervasive the virus is where trials are being conducted. Each
drugmaker has targeted a specific number of infections to trigger a
first analysis of their data.
HOW WELL ARE THE VACCINES SUPPOSED TO WORK?
The World Health Organization ideally wants to see at least 70%
efficacy. The FDA wants at least 50% - which means there must be at
least twice as many infections among volunteers who received a
placebo as among those in the vaccine group. The EMA has said it may
accept a lower efficacy level.
WHAT ABOUT RUSSIA AND CHINA?
While Pfizer's shot was the first to be rolled out following the
publication of full Phase III trial data, Russia and China have been
inoculating their citizens for months with several different
vaccines still undergoing late-stage trials.
Russia said on Nov. 24 its Sputnik V vaccine, developed by the
Gamaleya Institute, was 91.4% effective based on interim late-stage
trial results. It started vaccinations in August and has inoculated
more than 100,000 people so far.
India plans to make 300 million of the shots next year and Argentina
has given the greenlight for emergency use of the shot, with some
300,000 doses arriving in the country on Dec. 24.
China launched an emergency use programme in July aimed at essential
workers and others at high risk of infection. It has vaccinated
about one million people as of mid-November using at least three
shots - two developed by the state-backed China National Biotec
Group (CNBG) and one by Sinovac Biotech.
Trial data on a COVID-19 vaccine developed by China's Sinovac
Biotech has varied: interim data from a late-stage trial in Turkey
showed its CoronaVac shot is 91.25% effective, while researchers in
Brazil say the shot was more than 50% effective.
The United Arab Emirates, meanwhile, said on Dec. 9 that one of the
CNBG vaccines was 86% effective based on interim results from a
late-stage trial in the Gulf Arab state.
(Editing by Caroline Humer, David Clarke, Mark Potter, Josephine
Mason and Louise Heavens)
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