Moderna Says Its Coronavirus Vaccine Is 94.5% Effective Against Covid-19, a Crucial Victory in the Fight Against the Pandemic Posted byAndrew Dunn November 16, 2020 Leave a comment on Moderna Says Its Coronavirus Vaccine Is 94.5% Effective Against Covid-19, a Crucial Victory in the Fight Against the Pandemic The announcement closely follows similar news from a rival vaccine program by Pfizer and BioNTech, which touted late-stage success a week ago.