Efficacy of the second and third BNT162b2 vaccine doses
The prevalence of COVID-19 infection observed from the second vaccine dose and forward was 47.6% (59/124) among adolescents with AIIRD and 35% (28/80) among controls, p=0.5278 (Table 3). Most of the breakthrough infections (88%) occurred during the Omicron surge. During the Delta surge, the prevalence of infection was numerically higher in the patient group than in the healthy controls (n=7, 11% vs. n=1, 3%, p=0.1555).
The prevalence of a breakthrough infection was similar among patients with JIA and SLE. Time-to-infection following the last vaccination was similar among AIIRD patients compared to controls, at a median of 5.5 vs. 5.2 months, respectively; log-rank p=0.6499 (Figure 3). In both patient and control groups, all cases of COVID-19 infection were mild, with no severe infections or hospitalizations and no COVID-19 related complications.