Pfizer COVID-19 Vaccine Works in ‘Real World’ Test
A real-world test of Pfizer’s COVID-19 vaccine in more than half a million people confirms that it’s very effective at preventing serious illness or death, even after one dose.
Wednesday’s published results, from a mass vaccination campaign in Israel, give strong reassurance that the benefits seen in smaller, limited testing persisted when the vaccine was used much more widely in a general population with various ages and health conditions.
The vaccine was 92% effective at preventing severe disease after two shots and 62% after one.
Its estimated effectiveness for preventing death was 72% two to three weeks after the first shot, a rate that may improve as immunity builds over time.
It seemed as effective in folks over 70 as in younger people.
“This is immensely reassuring … better than I would have guessed,” said the Mayo Clinic’s Dr. Gregory Poland.
Vanderbilt University’s Dr. Buddy Creech agreed: “Even after one dose we can see very high effectiveness in prevention of death,” he said.
Neither doctor had a role in the Israel study but both are involved in other coronavirus vaccine work.
Both doctors also said the new results may boost consideration of delaying the second shot, as the United Kingdom is trying, or giving one dose instead of two to people who have already had COVID-19, as France is doing, to stretch limited supplies.