Ethnic homophily affects vaccine prioritization strategies

Abstract

People are more likely to interact with other people of their ethnicity - a phenomenon known as ethnic homophily. In the United States, people of color are known to hold proportionately more high-contact jobs and are thus more at risk of virus infection. At the same time, these ethnic groups are on average younger than the rest of the population. This gives rise to interesting disease dynamics and non-trivial trade-offs that should be taken into consideration when developing prioritization strategies for future mass vaccine roll-outs. Here, we study the spread of COVID-19 through the U.S. population, stratified by age, ethnicity, and occupation, using a detailed, previously-developed compartmental disease model. Based on historic data from the U.S. mass COVID-19 vaccine roll-out that began in December 2020, we show, (i) how ethnic homophily affects the choice of optimal vaccine allocation strategy, (ii) that, notwithstanding potential ethical concerns, differentiating by ethnicity in these strategies can improve outcomes (e.g., fewer deaths), and (iii) that the most likely social context in the United States is very different from the standard assumptions made by models which do not account for ethnicity and this difference affects which allocation strategy is optimal.

Projecting social contact matrices to populations stratified by binary attributes with known homophily

“…We showed that the disease dynamics can be very different when homophily is included in a model. A more elaborate, recent model uses this new methodology and shows that accounting for homophily with respect to ethnicity is important when designing optimal vaccine roll-out strategies [9]. This manuscript leaves several questions unanswered.…”