Fig. 2: Secondary antigenic challenge enhances antibody levels and neutralisation following primary Omicron infection.
From: Immunological imprinting of humoral immunity to SARS-CoV-2 in children
A Antibody levels specific for spike from Wuhan-Hu-1 and Omicron BA.1, BA.2, BA.4, and BA.5 were determined in children following primary BA.1/2 Omicron infection (green; n = 19), Omicron reinfection (purple; n = 13) and COVID-19 vaccination (blue; n = 11) after primary BA.1/2 infection. B Neutralisation of pseudovirus-bearing ancestral B.1 or Omicron variant spike protein in children following primary Omicron BA.1/2 infection (green; n = 19), Omicron BA.4/5 reinfection (purple; n = 13) or following COVID-19 vaccination after primary BA.1/2 infection (blue; n = 11). Data were presented as NT50, the titre at which infectivity had been reduced by 50% relative to controls. Dashed lines indicate the limit of detection. Kruskal–Wallis test with Dunn’s multiple comparisons test, bars indicate geometric mean ±95% CI. Data were presented as arbitrary units (AU)/ml. Source data are provided as a Source Data file.
