 The SARS-CoV-2-Armicron variant has subvariants with divergent properties, but relative vaccine effectiveness has not been characterized. Here, the authors show that mRNA vaccine effectiveness is similar for the subvariants Ba.1 and Ba.2, with a decline three months after the second dose and increase after the booster. This article was authored by Hayam Khimaitali, Hussain H.E.U.B., Sorsan Olmukdad, and others.