Figure 1.

Differential waning of RBD-binding IgG antibody levels based on vaccination and infection status. Naïve unvaccinated (n = 418) and infected unvaccinated (n = 290) show no change in antibody levels over time (p > 0.05); naïve, vaccinated participants (n = 515) and infected, vaccinated participants (n = 298) both show significant waning over the time (**** p < 0.0001). The antibody level of the naïve unvaccinated group was always lower than the other groups (**** p < 0.0001); the infected vaccinated group was always higher than any other group (** p < 0.0042); naïve, vaccinated group is higher than infected, unvaccinated group for the first 4 months after vaccination (** p < 0.0016). The rate of decay was only significantly different between the vaccinated and infected groups (**** p < 0.0001) but not between the two vaccinated (p = 0.7914) and the two unvaccinated groups (p = 0.9569). Number of months start with the time of reception of the primary vaccine series for the vaccinated groups, time of infection for the infected unvaccinated group, and the first available timepoint for the naïve unvaccinated group.