Pfizer vaccine shows strong real-world protection
A real-world test of the Pfizer/ Biontech vaccine in more than half a million people confirms that it’s very effective at preventing serious illness or death, even after one dose.
Yesterday’s published results, from a mass vaccination campaign in Israel, give strong reassurance that the benefits seen in smaller, limited testing persisted when the Covid-19 vaccine was used much more widely in a general population with various ages and health conditions.
The German and American 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 vaccine is given as two shots, three weeks apart, in most countries.
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 vaccines in December or January to an equal number of people of similar age, sex and health who did not receive vaccine. None of the participants had previously tested positive for the virus.
The vaccine was estimated to be 57 per cent effective at preventing any symptoms of Covid-19 two to three weeks after the first dose, and 94 per cent a week or more after the second dose. Effectiveness was 74 per cent after one shot and 87 per cent after two for preventing hospitalisation, and 46 per cent and 92 per cent for preventing confirmed infection. Reducing infections gives hope that the vaccine may curb spread of the virus, but this type of study can’t determine if that’s the case.
Single-shot vaccine effective Johnson & Johnson’s single-dose vaccine offers strong protection against severe Covid-19, according to an analysis released yesterday by US regulators that sets the stage for a final decision on a new and easier-touse shot to help tame the pandemic.
Food and Drug Administration scientists confirmed that overall the vaccine is about 66 per cent effective at preventing moderate to severe Covid-19, and about 85 per cent effective against the most serious illness. The agency also said J&J’S shot is safe. —AP