The initial omicron (B.1.1.529) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subvariants, BA.1 and BA.2 (BA.1/2), were progressively displaced by BA.5 in Japan, which showed not only higher transmittivity less pathogenicity, but also differences antibiotic use according to the difference clinical course of compared with BA.1/2 infections. patients received more antibiotics, espe...