Posted in Web Delta variant: Pfizer Covid vaccine 39% effective in … October 9, 2021 Pfizer and BioNTech’s Covid-19 vaccine is just 39% effective in Israel where the delta variant is the dominant strain, according to a new report from the country’s Health Ministry. https://www.cnbc.com/2021/07/23/delta-variant-pfizer-covid-vaccine-39percent-effective-in-israel-prevents-severe-illness.html