Symptomatic Covid-19 Cases Dropped 94% With Pfizer Vaccine, Israeli Data Show
Study comparing two groups of 600,000 people also found vaccine recipients 92% less likely to develop severe illness
TEL AVIV—The latest data from Israel shows a 94% drop in symptomatic Covid-19 infections among 600,000 people who received two doses of Pfizer Inc. and BioNTech SE’s vaccine, offering important new insights for other countries as they roll out their own campaigns.
The vaccinated group was also 92% less likely to develop severe illness from the disease, according to a study by Clalit, Israel’s largest healthcare provider. Clalit compared 600,000 people who got the shots with a group of the same size who didn’t in what was Israel’s largest vaccine study to date.
Clalit said the study, which was carried out with a team from Harvard University, included 430,000 people who were between 16 and 59 years of age, and 170,000 who were 60 or older. It was the first of its kind to show such a high level of efficacy for Pfizer’s vaccine for those aged 70 and over, due to the limited scope of the earlier clinical trials, according to the healthcare provider.
The study was done so that each vaccinated individual was tested against an unvaccinated person who had a similar profile, including their risk level for infection, risk level of developing serious illness and overall health.
“It is now unequivocal that Pfizer’s vaccine against the coronavirus is incredibly effective in real life one week after the second dose, just as was found in the clinical study,” said Ran Balicer, Clalit’s chief innovation officer and one of the study’s authors, in a Hebrew statement published Sunday with the study. The vaccine is even more effective two weeks after the second shot, he added.
The small Middle Eastern country, which leads the world in vaccinating against Covid-19 in terms of percentage of the total population inoculated, has already administered the first shot of a recommended two-dose regimen to about 42% of its roughly nine million population since beginning its program on Dec. 20. About 28% of the entire population is fully vaccinated, according to data from Israel’s health ministry.
After beginning its vaccine campaign with healthcare workers and those over 60 years old, Israel earlier this month opened it up to everyone over 16.
Vaccinating people in Israel—whose population is about the same as New York City’s—is relatively simple compared with the mass mobilizations needed by countries such as the U.S. that have many more people spread over a greater sweep of geography. But Israel’s advanced and fully digitized healthcare system, in which every citizen by law belongs to one of four healthcare providers, has been crucial to the speed of the drive, Israeli health officials have said.
These healthcare providers have a presence in nearly every city, town and village and can mobilize their patients through text messages and phone calls to go get vaccinated.
Israeli health officials also gave priority to simplicity and speed from the start, making the vaccine available to anyone 60 years and older, and then gradually opened up the drive to more age groups. When vaccines were left over at the end of the day, in most cases anyone over 16 was allowed to get the shots. The government also reached out to communities less likely to get vaccinated.
It also encouraged people to get the shots by making it clear from the start that those vaccinated will be granted certain privileges, such as access to museums, gyms or international travel without quarantining.
Israel aims to inoculate most of its population by March, a goal made possible after it paid a premium for early shipments from Pfizer and agreed to share data about its vaccine—from effectiveness to side effects. It also placed orders with other vaccine companies, including Moderna Inc. and AstraZeneca PLC.
After imposing a third lockdown in December to contain a resurgence in infections, Israel in recent days has loosened restrictions somewhat. It has allowed unrestrained travel within the country, opened national parks, allowed takeaway service from restaurants and permitted larger outdoor gatherings. But most schools and businesses remain closed and nearly all international flights are banned.
Israel temporarily shut its only international airport late last month to halt the spread of new Covid-19 variants in the country. Authorities say the more infectious and possibly more deadly British variant, known as B.1.1.7, has become the dominant strain in Israel over the past month.
In recent days, the country’s overall daily infections have greatly decreased, dropping from a seven-day average of over 8,000 in mid-January to below 5,000 on Monday.
The government is looking to reopen restaurants, museums and cultural sites to vaccinated people in the coming weeks. It is also working on tourism deals with nearby Cyprus and Greece to allow inoculated Israelis to soon travel there without quarantining.
While Israel only began gradually exiting a strict lockdown eight days ago, researchers at the Israel-based Weizmann Institute of Science found that in relation to previous lockdowns, hospitalizations and serious illness among those first vaccinated, meaning those 60 and older, dropped 48%, while deaths decreased 50% among that group. For those aged 55-60, the next most-vaccinated group, researchers found a 36% decrease in hospitalizations and 30% decrease in serious illness.
“Gradually the groups that are further away from their vaccination start date become less and less hospitalized,” said Eran Segal, a computational biologist at the Weizmann Institute. “It’s beautiful.”