A large, real-world study of half a million people found that the BioNTech-Pfizer coronavirus vaccine is 94% effective.
The article was published in New England Journal of Medicine on Wednesday and involved the study of 1.2 million people during Israel’s mass vaccination campaign.
What did the study reveal?
The study showed that two injections of the BioNTech-Pfizer vaccine cut symptomatic cases of COVID-19 by 94% across all age groups, while a single injection was 57% effective in protecting against symptomatic infections after two weeks.
The vaccine was also found to be 92% effective in preventing serious illness after two vaccines and 62% after one, the peer-reviewed study found.
The study’s results were close to those of last year’s clinical trials for the Pfizer-BioNTech vaccine, which found two doses with 95% effectiveness.
He showed that there can be a strong protective benefit against infection, a factor that is considered crucial to stop progressive transmission.
How was the study conducted?
The study was conducted by researchers from the Clalit Research Institute and the Ben-Gurion University of the Negev, in Israel, together with Harvard University, in the United States.
The research was carried out between December 20, 2020 and February 1, 2021, when the British variant of the coronavirus was spreading across Israel.
The study compared nearly 600,000 people aged 16 and over in Israel’s largest health organization who received doses of Pfizer-BioNTech in December or January with an equal number of people of the same age, gender and health who did not receive the injection.
None of the participants had contracted the virus in the past.
Lead author Noam Barda, head of epidemiology and research at the Clalit Research Institute, told the AFP news agency that the matching process was highly robust.
The results were recorded on days 14-20 after the first injection and on days seven or later after the second.
Researchers ‘surprised’ by the results
The study’s senior author, Ran Balicer, said the results showed that the BioNTech-Pfizer vaccine is “extremely effective in the real world” after the second dose.
“We were surprised because we expected that in the real world scenario, where the cold chain is not maintained perfectly and the population is older and sicker, you will not get results as good as in controlled clinical trials,” said Balicer Reuters news agency.
“We showed that the vaccine is so effective in very different subgroups, in young and old, with no comorbidities and few comorbidities,” he added.
dvv / rs (AFP, AP, Reuters)