Stuart ASV, Shaw RH, Liu X, et al. Immunogenicity, safety, and reactogenicity of heterologous COVID-19 primary vaccination incorporating mRNA, viral-vector, and protein-adjuvant vaccines in the UK (Com-COV2): a single-blind, randomised, phase 2, non-inferiority trial. Lancet 2022; 399: 36–49—In this Article, the X axis for figure 3B has been updated to read 14 days since boost vaccination. This correction has been made to the online version as of Feb 24, 2022.