LONDON—The U.K.’s rollout of Pfizer Inc. and BioNTech SE ’s Covid-19 vaccine has led to a substantial drop in infections in people 80 and over, according to preliminary data that adds to a growing body of evidence that the shots provide significant if not complete protection against the disease.
The data from the U.K., published Monday, is preliminary and hasn’t been reviewed by other scientists. It provides reasons for optimism that vaccines offer a route out of a pandemic that has claimed at least 2.5 million lives world-wide and sickened tens of millions.
New data includes an analysis of the effect of vaccinations in the elderly, a study looking at infection among vaccinated and unvaccinated healthcare workers, and a broad look at vaccinations in Scotland that covered more than five million people.
England’s public health agency said that one shot of the vaccine developed by Pfizer and BioNTech led to a 57% reduction in cases of Covid-19 in people aged 80 or over, compared with what would have been expected had they not received a shot. This rose to 88% after a second dose.
Hospitalization rates fell 41% just 14 days after injection and the chance of dying from the disease was more than halved among those immunized.