In line with this, MBC frequency against Wuhan Hu-1, B.1.617.2 (Delta) and B.1.1.529 (Omicron) S1 and RBD proteins increased in three-dose vaccinated, infection-naïve individuals, but not those imprinted by previous Wuhan Hu-1 infection (Fig. 4F). The gene discussed is PSMD1; the disease is infection.