The SARS-CoV-2 Omicron variant is associated with high rates of vaccine breakthrough infections, but the immunological basis for this is not well characterised. Here, the authors show that increased anti-Spike IgG antibody levels are associated with a reduced risk of infection with the Delta variant, but not with Omicron.
- Nina Breinholt Stærke
- Joanne Reekie
- Ole Schmeltz Søgaard
