How Vaccination Helps to Relax the Population Mobility: An Agent-Based Model Approach

There is an ongoing debate on the relative impact of the various nonpharmaceutical interventions employed to limit the spread of coronavirus disease 2019 (COVID-19). This study examined the combined effect of vaccination and mobility using an agent-based model of an urban neighborhood with nine boroughs. The model was not designed to match a specific geographical area but calibrated to match the well-known key characteristics of COVID-19. Several strategies were examined, including local and global mobility control and different vaccination coverages. We found that local mobility control is beneficial in reducing peak size. Suppressing mobility between patches is ineffective when the infection is initially uniformly distributed. However, mobility control becomes efficient when low- and high-risk patches exist. A key finding is that high vaccination coverage in this case (≥75%) is sufficient to contain the disease without mobility restrictions. Lower vaccination levels must be combined with a mobility restriction level suited for the population depending on their age. The infection among young populations can be controlled with no mobility restrictions at 50% vaccination coverage. Controlling the disease in older populations is more challenging, indicating the need for prioritizing vaccination among this group.