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The Pfizer Inc. and The BioNTech SE Covid-19 vaccine appeared to prevent the vast majority of recipients in Israel from becoming infected, providing the first real-world indication that the immunization will slow the transmission of the coronavirus.
The vaccine, which was rolled out in a national immunization program beginning Dec. 20, was 89.4% effective in preventing laboratory-confirmed infections, according to a copy of a draft publication posted on Twitter and confirmed by a person known with the work. The companies and the Israeli Ministry of Health collaborated on the preliminary observational analysis, which has not yet been peer-reviewed.
The results, also reported in Der Spiegel are the latest in one series of positive data comes from Israel, which has given more Covid vaccines per capita than anywhere else in the world. Nearly half of the population has had at least one dose of vaccine. Separately, Israeli authorities said on Saturday that the Pfizer-BioNTech shot was 99% effective preventing deaths from the virus.
More than 202 million shots delivered: Covid-19 Tracker
The initial results of laboratory-confirmed infections are important because they show that the vaccine can also prevent asymptomatic carriers from spreading the virus that causes Covid-19, something that was not clear until now. Stopping the transmission in this way is a key factor as countries try to lift contact restrictions and reopen economies.
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Pfizer and BioNTech said they are working on a real-world analysis of data from Israel, which will be shared once completed. Spokespersons declined to comment on unpublished data.
Four-fifths of the virus cases in Israel during the study period, January 17 to February 6, were the more transmissible strain first identified in the UK. Israel’s vaccination program began just before the so-called B.1.1. 7 variant emerged, feeding infections and triggering a third lockdown on Jan. 8.
Until February 6, about 27% of the people deprecated 15 years and older in Israel were fully vaccinated, with the Pfizer-BioNTech injection being the only vaccine available in the country at the time. Humans were considered fully vaccinated and included in the analysis if the data collected was more than 7 days after receiving their second dose.
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