ACE and diabetes mellitus: Restricting the post-booster analysis to the post-Omicron period led to the inclusion of general health in the fully adjusted model, which was not found to be associated with risk of breakthrough infection, and the exclusion of educational attainment, frontline worker status, inter-vaccine interval, diabetes, and use of beta blockers, ACE inhibitors, and angiotensin receptor blockers (appendix Table S12).