By Dov Lieber
TEL AVIV -- The Covid-19 vaccine from Pfizer Inc. and BioNTech
SE is equally effective across all age groups, including those over
60, according to a new Israeli study, in a boost of confidence to
global vaccine efforts.
The Pfizer vaccine provided around 94% protection against
developing coronavirus symptoms across all age groups above 16 a
week after the second shot of a recommended two-dose regimen,
according to a study by researchers from Israel's Clalit Research
Institute and Harvard University. The study also found the vaccine
is 92% effective in preventing severe disease.
The results are in line with the vaccine maker's own clinical
trial, but the large size of the study, which covered nearly 1.2
million people, provides more precise insight into older age groups
that were sparsely covered by the drugmaker's trial, according to
the study's authors.
The peer-reviewed study, parts of which have been reported
previously, was published Wednesday in the New England Journal of
Israel is the only country that has begun vaccinating all age
groups over 16 in relatively large numbers, as part of its campaign
to inoculate a majority of its nine-million population by
The pace of Israel's inoculation drive and its technologically
advanced healthcare system have allowed researchers to gather
real-world data on the vaccine -- from effectiveness to side
effects -- and given them an unprecedented view into vaccine's
effect across varied age groups. The results offer important new
insights for other countries as they roll out their own
Researchers on this study were able to look at data from around
1.2 million people and two decades' worth of their health records.
As the study was observational in nature, the researchers worked to
minimize any biases between the vaccinated versus unvaccinated
group that might account for better results, such as better health
To do this, they matched each vaccinated individual against an
unvaccinated person who had a similar profile, including their risk
level for infection, risk level of developing serious illness and
This study provides "scientifically validated real-world
evidence of the effectiveness of the vaccine," said Prof. Ran
Balicer, Clalit's chief innovation officer and one of the study's
Israel is leading the world in the global vaccine race. Over
half of its population has received the first shot, including 90%
of those over 60, and about a third of the country is fully
vaccinated, according to Israel's Health Ministry. After beginning
its campaign on Dec. 20 with healthcare workers and the elderly,
Israel earlier this month opened it up to everyone over 16.
The findings of the Clalit study were similar to recently
published research out of the U.K. and from other Israeli
researchers that just one Pfizer shot can offer strong
One dose of Pfizer's vaccine was found to be 57% effective in
preventing symptomatic Covid-19 and 62% effective at preventing
severe disease 14 to 20 days after the first dose, the study found.
Pfizer's own clinical study also found one dose to be 57% effective
in preventing symptomatic Covid-19.
The vaccine is also highly effective for those with one to two
pre-existing health conditions, the study's authors said. But they
said more testing would be needed to understand how effective the
vaccine is for those with three or more pre-existing
The Israeli study included more than 110,000 people over the age
of 70, and more than 40,000 people over 80. In both cases, the
study showed their protection was equal to any of the younger age
Most countries launched their vaccination programs by first
targeting the elderly, but didn't have enough data at the time on
its efficacy to support that move. Pfizer's original clinical
trial, owing to its small scale, didn't have granular insight into
adults 70 years or older, according to Mr. Balicer.
The large size of the Israeli data pool allowed researchers to
look closely at each different age bracket.
Israel paid a premium for the vaccine and agreed to share
related data for early shipments from Pfizer. It also placed orders
with other vaccine companies, including Moderna Inc. and
The aggressive vaccination campaign has paved the way for the
country's reopening. In recent months, Israel has suffered through
some of the world's worst infection rates per capita, as many
flouted lockdowns, and more recently, a British variant of the
disease ran rampant.
On Saturday evening, Israel began issuing so-called green
passports that allow vaccinated people to enter gyms, concerts and
hotels. The passes will later be used at restaurants and bars when
they reopen in the coming weeks.
--Jared Hopkins in New York contributed to this article.
(END) Dow Jones Newswires
February 24, 2021 17:14 ET (22:14 GMT)
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