Pfizer and BioNTech's Covid-19 vaccine showed 94 per cent efficacy in a real world study conducted in Israel involving 1.2 million people. The findings published in the New England Journal of Medicine showed that the vaccine performed as well as it did in the clinical trials.

In this study, all persons who were newly vaccinated during the period from December 20, 2020, to February 1, 2021, were matched to unvaccinated controls in a 1:1 ratio according to demographic and clinical characteristics. Each study group included 596,618 persons.