Entertainment Pfizer/BioNTech say COVID-19 vaccine likely to prevent asymptomatic infection By Qatarday - March 11, 2021 0 349 Facebook Twitter Pinterest WhatsApp Pfizer Inc and BioNTech SE said on Wednesday that real-world data from Israel suggests that their COVID-19 vaccine is 94% effective in preventing asymptomatic infections, meaning the vaccine could significantly reduce transmission.