Pfizer vaccine Photograph:( Reuters )
Pfizer's vaccine, the study found, was 94 per cent effective against symptomatic Covid-19 seven or more days after the second dose was administered
A massive study involving 1.2 million people published on Wednesday showed that Pfizer-BioNTech's coronavirus vaccine is 94 per cent effective.
For the Israeli study, published in the New England Journal of Medicine, nearly 600,000 people received Pfizer's drug and an equal number of people did not receive the shots.
The people involved in both groups had similar characteristics, like age, sex, medical condition, among others.
Pfizer's vaccine, the study found, was 94 per cent effective against symptomatic Covid-19 seven or more days after the second dose was administered.
However, the efficacy for symptomatic patients reduced to 57 per cent between 14-20 days after the first dose.
The results of this Israeli study is close to the 95 per cent efficacy that Pfizer achieved during Phase 3 clinical trials.
It also found people who received the second shot had a 92 per cent lower chance of getting any form of infection at all compared to those who were not vaccinated.
"This is the first peer-reviewed large scale evidence for the effectiveness of a vaccine in real world conditions," Ben Reis, a researcher at Harvard Medical School and one of the study's authors, told news agency AFP.
The study was conducted between December 20, 2020 and February 1, 2021, a period when a newer variant first confirmed in the UK was rampant in Israel, suggesting that the vaccine works well against the variant that has alarmed experts across the world.