Pfizer Vaccine 85% Effective After First Dose, Study Finds

by DailyHealthPost Editorial

The Pfizer/BioNTech vaccine greatly reduces Covid transmission. The new Israeli study published in The Lancet medical journal looked at the effectiveness of the first dose in more than 7,000 healthcare workers.

The Sheba Medical Centre research found there was an 85% reduction in the number of people developing symptomatic Covid-19 between 15 and 28 days after the jab. Overall infections, including among asymptomatic patients, were reduced by 75%.

The study said the data showed “substantial early reductions in SARS-CoV-2 infection and symptomatic Covid-19 rates following first vaccine dose administration.” The findings support “delaying the second dose in countries facing vaccine shortages and scarce resources, so as to allow higher population coverage with a single dose.” However, the study also said more research is needed on the long-term effectiveness of a single dose “to inform a second dose delay policy.”


Pfizer said in a statement it was doing its own analysis of “the vaccine’s real-world effectiveness in several locations worldwide, including Israel” and would not comment directly on the findings.

Deborah Dunn-Walters, professor of immunology at the University of Surrey, said: “It should be noted that this study was carried out on people of working age, so it will be informative to see a similar study in older people after one dose.

“Although further research is needed, overall these new findings should provide reassurance around the UK’s decision to offer the two doses of the vaccine 12 weeks apart.”

Dr Peter English, consultant in communicable disease control, added: “This is good news. It supports earlier data suggesting that, from six weeks or so after vaccination, vaccine efficacy is likely to be at least 85% – possibly considerably better – at least in vaccine recipients of working age.”

Israel’s vaccination campaign is, by a significant margin, the world’s fastest. Nearly half of its population has been inoculated with one shot and almost a third has been fully vaccinated with two.