Fig. 1.

Study profile. Prospective study cohort involving health care workers vaccinated with inactivated SARS-CoV-2 (CoronaVac). Serology assays were conducted at 1, 3, and 5 months following the second vaccination dose. A total of 20 participants were excluded or dropped out during the study, most of whom were excluded due to infection with SARS-CoV-2 during the course of the study. Of the two participants who dropped out, one died due to non-COVID-19 disease, whilst the other one objected to continue to participate due to reluctance to travel to the assessment centre.