Moderna says its Covid-19 shot remains 93% effective 4-6 months after second dose

NEW YORK (Reuters): Moderna Inc said on Thursday (Aug 5) its Covid-19 shot was about 93% effective four to six months after the second dose, showing hardly any change from the 94% efficacy reported in its original clinical trial.

That compares favourably to data released by rivals Pfizer Inc and BioNTech SE last week in which they suggested their vaccine's efficacy waned around 6% every two months, declining to around 84% six months after the second shot. Both the Moderna and Pfizer-BioNTech vaccines are based on messenger RNA (mRNA) technology.