ABSTRACT
Disease outbreaks often highlight existing inequalities and injustices within society. The COVID 19 pandemic has underscored long-existing health inequalities, both within countries and between the Global North and South. These disparities have been observed throughout the pandemic, from disparities in the severity and impact of the initial waves of cases to disparities in who was most protected during the roll-out of vaccination. As the Delta variant surges in many countries, structural inequalities shape the trajectory of the pandemic and exacerbate existing health disparities. In the age of vaccination, the double burden of disparities in both exposure to infection and vaccination coverage intersect to determine the current and future patterns of infection, immunity, and mortality. It is important to consider the ways in which these disparities, with overlapping but distinct drivers, interact to determine population-level immunity and the burden of COVID 19 in different communities. Individuals or communities can experience different pathways to immunity, whether through infection, vaccination, or both. Using San Francisco as a case study, we show how a seroepidemiological approach can illuminate disparities in the pathway to immunity.