Tracking human activity in real time and at fine spatial scale is particularly valuable during episodes such as the COVID-19 pandemic. In this paper, we discuss the suitability of smartphone data for quantifying movement and social contact. We show that these data cover broad sections of the US...

As countries transition from facing COVID-19 vaccine supply shortfalls to requiring novel strategies to facilitate vaccination, modern retail chains--often designed and located to target particular demographic groups--are a potential vaccine delivery vehicle. Using geospatial data, we quantify...