Figure 1.

Neutralizing responses against the Wuhan strain and XBB1.5 strain. (A) distribution of neutralizing responses in the entire cohort, (B) comparative distribution of neutralizing responses: naive vs. previously infected, (C) distribution of neutralizing responses relative to time elapsed since last vaccination, months; M, (D) age-stratified distribution of neutralizing responses, years old; y.o., (E) vaccine type-specific distribution of neutralizing responses and (F) distribution of neutralizing responses by number of vaccine doses administered. 126 participants (9.3%) received three doses of an ancestral-strain monovalent vaccine (V3 group). 467 (37.5%) received three doses of a monovalent vaccine and one dose of a bivalent vaccine (V3+Bi group), 56 (4.1%) were administered four doses of the monovalent vaccine (V4 group), and 704 (52.0%) received four doses of a monovalent vaccine and one dose of a bivalent vaccine (V4+Bi group). *; p<0.05, **; p<0.01, ***; p<0.001.