Reduced efficacy of AZD7442 in neutralizing SARS-CoV-2 Omicron variants. (A-B) Neutralization titers against different SARS-CoV-2 variants of concern after administration of AZD7442 (N = 28). (C) Neutralization titers against WA1 and Delta increased substantially after AZD7442 administration but were less pronounced against Omicron variants. No statistically significant increase in neutralizing titers was observed for BA.1, BQ.1.1, or XBB. Number represents the median fold change after AZD7442. For all graphs, the horizontal dotted line represents the limit of detection. ∗P ≤ .05, ∗∗P ≤ .01, ∗∗∗P ≤ .001, ∗∗∗∗P ≤ .0001 using Friedman tests and Dunn test or Wilcoxon test to correct for multiple comparisons, as appropriate. GMT, geometric mean antibody titer.