In this cohort study, the authors investigate the risk of severe outcomes following infection from Omicron BA.1 and BA.2 sub-lineages. Using whole genome sequencing and electronic health record data for ~980,000 BA.1 and ~250,000 BA.2 cases in England, they find a slightly lower risk of death and hospitalisation associated with BA.2.
- H. H. Webster
- T. Nyberg
- S. Thelwall
