Last checked at 
* Turkey is second trial site to report results for
Sinovac's shot
* Late-stage interim results show 91.25% efficacy for
CoronaVac
* Turkey says it will receive first shipment from China on
Monday
* Turkey will also buy 4.5 mln doses of Pfizer/BioNTech
vaccine
(Adds details, background)
By Tuvan Gumrukcu and Ali Kucukgocmen
ANKARA, Dec 24 (Reuters) - A COVID-19 vaccine developed by
China's Sinovac Biotech is 91.25% effective, according
to interim data from a late-stage trial in Turkey, a potentially
much better result than reported from a separate trial of the
vaccine in Brazil.
Researchers in Brazil, which is also running a final Phase
III trial of the vaccine, said on Wednesday the shot was more
than 50% effective, but withheld full results at the company's
request, raising questions about transparency.
Turkish researchers said on Thursday no major side-effects
were seen during their trial, apart from one person who had an
allergic reaction. Common adverse effects caused by the vaccine
were fever, mild pain and slight fatigue, they said.
The Turkish trials began on Sept. 14 and have included more
than 7,000 volunteers, the researchers said, adding the results
announced on Thursday were based on data from 1,322 people.
Sinovac is the first Chinese vaccine maker to release
details from late-stage clinical trials, following positive
results from rival products developed by Pfizer, Moderna
and AstraZeneca last month.
The Turkish researchers, speaking alongside Health Minister
Fahrettin Koca, said 26 of the 29 people who were infected
during the trial were given placebos, adding the trial would
continue until 40 people become infected.
"We are now certain that the vaccine is effective and safe
(to use) on Turkish people," Koca said, adding Ankara would use
the data for licensing the vaccine.
He also said that researchers initially planned to announce
the results after 40 people were infected, but that the findings
showed the volunteers had minimal adverse effects after the shot
and that it was therefore deemed safe.
"Despite it being risky, we saw a very light picture where
three people's PCR (COVID test) were positive, with no fever or
respiratory problems... We can easily say that despite it being
risky, those three people went through it very lightly," he
said.
SHIPMENTS ARRIVE MONDAY
Turkey had agreed to buy 50 million doses of Sinovac's shot
and receive delivery by Dec. 11 but the shipment was delayed.
Koca said three million doses would arrive on Monday, adding
that Turkey would vaccinate some nine million people in the
first group, starting with health workers.
Sinovac has also signed supply deals for its vaccine, called
CoronaVac, with countries including Indonesia, Brazil, Chile and
Singapore, and is negotiating with the Philippines and Malaysia.
CoronaVac has been given to tens of thousands of people
under an emergency use programme China launched in July
targeting specific groups of high-infection risks.
CoronaVac is based on traditional vaccine technology that
uses inactivated coronavirus that cannot replicate in human
cells to trigger an immune response.
Vaccines developed by Pfizer/BioNTech and Moderna
use a new technology called synthetic messenger RNA (mRNA) to
activate the immune system against the virus and require far
colder storage.
Pfizer's treatment is the first fully tested COVID-19 shot
to be administered, with rollout already under way in Britain
and the United States.
Koca said Turkey would sign a deal with Pfizer/BioNTech for
4.5 million doses of their vaccine to be delivered by the end of
March, with an option to buy a further 30 million doses later.
On Thursday, Turkey's death toll from the coronavirus rose
by 254 to 19,115, according to Health Ministry data, while the
total number of COVID-19 infections rose by 18,102.
(Reporting by Tuvan Gumrukcu and Ali Kucukgocmen; Additional
reporting by Can Sezer in Istanbul and Roxanne Liu in Beijing;
Editing by Alex Richardson, Mark Potter and Nick Macfie)
