Pfizer-BioNTech's Covid-19 vaccine appears to reduce symptomatic coronavirus infections by more than 90% in the real world, Israeli researchers said Sunday.
The findings, while preliminary, suggest that the vaccine remains remarkably effective in a mass vaccination campaign -- outside the carefully controlled conditions of a clinical trial.
The Clalit Research Institute, part of a large Israeli health system, analyzed data on 1.2 million people, about half of whom had received the Pfizer-BioNTech vaccine. Researchers compared patients who received the vaccine with similar individuals who hadn't.
The rate of symptomatic Covid-19 -- meaning people who were infected with the coronavirus and felt sick -- decreased by 94% among people who received two doses of the vaccine, according to a press release from Clalit. The rate of serious illness decreased by 92%.
---from CNN
