A) Study layout. B-G) Antibody binding and neutralization titers of infants and adults with COVID-19. B) Antibody binding titers to WT strain in longitudinal samples from infants taken before (Pre, n=27), during (Acute, n=19), and after (Conv, n=30) infection. Dotted lines indicate days 0 and 30 post PCR+. C) Neutralizing antibody titers to Wuhan strain. D) Binding titers to WT strain in adults (Acute, n=13; Conv n=10) and infants (Acute n=13, Conv n=30). E) Neutralizing titers to Wuhan strain in adults (Acute n=15) and infants (Acute n=13, Conv n=30). F, G) Neutralizing titers against different variants in infants (Non-Omicron n=13, Omicron n=18, Conv n=30). D-G) Shown are only samples > 5 days post-infection. Statistical comparisons with Wilcoxon rank sum test. See also Figure S1