Abstract for: Fair allocation of COVID-19 vaccines: a system dynamics model for sub-prioritization of socioeconomically vulnerable population

Assessing health inequality has become crucial in health ethics during the COVID-19 pandemic. The pandemic has highlighted the preexisting link between socioeconomic vulnerability and poorer health outcomes. In England, vaccine allocation guidelines have faced significant criticism for being unfair, primarily due to neglecting socioeconomic factors. This study introduces a novel vaccine prioritization strategy that integrates age-stratified medical considerations with socioeconomic factors, utilizing the Index of Multiple Deprivation (IMD) for England. The proposed strategy prioritizes vaccination for socioeconomically vulnerable groups within the same age cohort until a specific threshold is reached. Behaviorally and structurally validated with official COVID-19 data from England, the extended SIR model shows that this sub-prioritization enhances fairness and reduces overall mortality. Additionally, the study explores demographic variations, revealing that a larger elderly population increases mortality and exacerbates inequity. In comparison, a younger population leads to more deaths among the young but with less inequity. Higher thresholds improve fairness, particularly when the vulnerable population is smaller. However, enhancing living conditions for vulnerable groups remains essential to achieve full outcome equity. This research provides valuable insights for policymakers to improve fairness and reduce mortality in future pandemics.