On Sunday, Israel's largest healthcare provider, Clalit Health Services, provided data that showed a 94% drop in symptomatic COVID-19 infections in people who received two doses of Pfizer and BioNTech's vaccine.
On top of that, Clalit's study showed that the same group of vaccinated people were 92% less likely to contract severe illnesses linked to COVID-19.
This mark's the largest "real world" study of the vaccine's performance: 1.2 million vaccinated and non-vaccinated participants took part in the study. Half of the participants were administered Pfizer's vaccine, the other half weren't.
"It shows unequivocally that Pfizer’s coronavirus vaccine is extremely effective in the real world a week after the second dose, just as it was found to be in the clinical study," said Ran Balicer, Clalit’s chief innovation officer.
What the clinical study discovered
Not only does the vaccine have a high percentage success rate, The Jerusalem Post reported that it also found that it was equally effective for people aged 70 and above as it was for younger people. In the study, some 170,000 vaccinated participants were over 60 years old.
Mirroring Pfizer's own clinical studies, Clalit's study found that the vaccine was most effective one week after the second dose was administered. And as a start of further results, the vaccine was found to potentially have an even higher rate for the prevention of symptomatic and severe disease after 14 days or more of being vaccinated.
Both groups of participants were matched on the level of risk of catching COVID-19, age, health, and more, explained Clalit. The healthcare provider is expected to publish its full results in the coming few weeks.
As Reuters points out, Israel has acted speedily in rolling out the COVID-19 vaccine to its residents, offering a database with insights into the vaccine's effectiveness, and by when countries could expect herd immunity to kick in.