Milwaukee, United States: A real-world test of Pfizer’s COVID-19 vaccine in more than half a million people has confirmed it is very effective at preventing serious illness or death, even after one dose.
Results from a mass vaccination campaign in Israel published on Thursday AEDT give strong reassurance that the benefits seen in smaller, limited testing persisted when the vaccine was used much more widely in aresear general population with various ages and health conditions.
The vaccine was 92 per cent effective at preventing severe disease after two shots and 62 per cent after one. Its estimated effectiveness for preventing death was 72 per cent two to three weeks after the first shot, a rate that may improve as immunity builds over time.
It seemed as effective in people over 70 as in younger people.
The study was led by researchers from the Clalit Research Institute and Ben-Gurion University of the Negev in Israel, with Harvard University in the US. It did not report on safety of the vaccine, just effectiveness, but no unexpected problems arose in previous testing.
Researchers compared nearly 600,000 people 16 and older in Israel’s largest healthcare organisation who were given shots in December or January to an equal number of people of similar age, sex and health who did not receive a vaccine. None of the participants had previously tested positive for the virus.
Read the article by Marilynn Marchione in The Sydney Morning Herald.