Moderna says that its vaccine (in which Mexico participates) is 94.5% effective against COVID-19 Posted byAndrew Dunn November 16, 2020 Leave a comment on Moderna says that its vaccine (in which Mexico participates) is 94.5% effective against COVID-19 The announcement closely follows similar news from a rival Pfizer and BioNTech vaccine program, which touted success in the last stage a week ago.