Coortes virtuais e dinâmica de anticorpos: uma abordagem computacional para regimes de vacinação com ChAdOx1 nCoV-19

Abstract

This study investigates the immune response induced by the ChAdOx1 nCoV-19 vaccine, encompassing both primary immunization and booster doses. A mathematical model was developed to simulate the immune dynamics under different vaccination regimens and calibrated using clinical cohort data. To enhance the robustness of the analyses, a Virtual Cohort comprising more than 16,000 individuals was constructed by sampling biologically plausible parameter sets capable of reproducing the observed antibody trajectories. In silico experiments were conducted to evaluate five vaccination scenarios in adults (18–55 years), including two-dose regimens and booster strategies administered at intervals of 8–12, 15–25, and 44–45 weeks, as well as a three-dose regimen. Additionally, exploratory simulations were performed with systematic variation of the inter-dose interval to identify schedules that maximize both the magnitude and duration of the immune response. Model predictions were compared with longitudinal data from a cohort followed for one year after booster administration, showing good agreement with the observed antibody kinetics. The analysis of the Virtual Cohort enabled the identification of dosing intervals associated with more sustained immune responses in both two- and three-dose regimens. These findings highlight the potential of computational modeling, combined with virtual populations, as a tool to support the design of vaccination strategies. Furthermore, simulations involving fractional dosing suggest immune responses comparable to those obtained with the standard dose, in agreement with evidence reported in the literature.