Overview of TAG-CO-VAC and December 2025 Preparations The World Health Organization’s Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continues to monitor the genetic and antigenic evolution of SARS-CoV-2, immune responses to natural infection and vaccination, and how vaccines perform against circulating variants. In anticipation of its December 2025 meeting, TAG-CO-VAC outlines the data it…