Pfizer Vaccine Found 94% Effective in Real World

The first big real-world study of the Pfizer/BioNTech vaccine to be independently reviewed shows the shot is highly effective at preventing COVID-19, in a potentially landmark moment for countries desperate to end lockdowns and reopen economies.

Up until now, most data on the efficacy of COVID-19 vaccines has come under controlled conditions in clinical trials, leaving an element of uncertainty over how results would translate into the real world with its unpredictable variables.

The research in Israel – two months into one of the world’s fastest rollouts, providing a rich source of data – showed two doses of the Pfizer shot cut symptomatic COVID-19 cases by 94% across all age groups, and severe illnesses by nearly as much.

The study of about 1.2 million people also showed a single shot was 57% effective in protecting against symptomatic infections after two weeks, according to the data published and peer-reviewed in the New England Journal of Medicine on Wednesday.

The results of the study for the Clalit Research Institute were close to those in clinical trials last year which found two doses were found to be 95% effective.

“We were surprised because we expected that in the real-world setting, where cold chain is not maintained perfectly and the population is older and sicker, that you will not get as good results as you got in the controlled clinical trials,” senior study author Ran Balicer told Reuters. “But we did and the vaccine worked as well in the real world.”

“We have shown the vaccine to be as effective in very different sub-groups, in the young and in the old in those with no co-morbidities and in those with few co-morbidities,” he added.

The study also suggests the vaccine, developed by U.S drugmaker Pfizer and Germany’s BioNTech, is effective against the coronavirus variant first identified in the UK. Researchers said they could not provide a specific level of efficacy, but the variant was the dominant version of the virus in Israel at the time of the study.

The research did not shed light on how the Pfizer shot will fare against another variant, now dominant in South Africa, that has been shown to reduce the efficacy of other vaccines.