F8 Studio/Shutterstock Zania Stamataki, University of Birmingham There was – rightfully – a lot of excitement when Pfizer and BioNTech announced interim results from their COVID vaccine trial. The vaccine, called BNT162b2, was reported to have an “efficacy rate above 90%”. This was soon translated in the press to be 90% “effective” at preventing COVID-19. … Continue reading Pfizer vaccine: what an ‘efficacy rate above 90%’ really means