The Interaction of Public Health Emergencies: Understanding Nation-wide and City-wide Spatiotemporal Dynamics of COVID-19 Transmission in a Warming World

Program Summary I am an early-stage investigator and recent KL2 scholar who has used econometric and spatiotemporal meth- ods to examine the propagation of C-19 in vulnerable populations. The focus of this R03 is to build on this work to examine the interaction between two devastating public health emergencies: the COVID-19 (C-19) pan- demic and climate change-amplified extreme heat events (EHEs). Although coronaviruses in general survive longer in environments of lower humidity, temperature, and sunlight, C-19 propagation has surged in summer months. A proposed explanation is that SARS-COV2 remains stable in hotter, humid environments, and that C- 19 transmission is promoted by heat-avoidant behavior that increases indoor physical proximity and air condi- tioner use. EHEs adversely affected one in five Americans. Thus, EHEs may intensify C-19 propagation, partic- ularly among more individuals and subpopulations vulnerable to both C-19-related and EHE-related morbidity and mortality – older aged individuals with medical comorbidities, socioeconomically disadvantaged individu- als, and minorities. An examination of this interaction will provide the first evidence of the association between climate-amplified EHEs and C-19, providing important data for future pandemic preparedness and climate-am- plified infectious disease propagation – a critical area of inquiry as described by several institutions, including the Federal Government. This proposal’s central objective is to examine the relationship between EHEs and C- 19 propagation, providing data that can subsequently be translated into future tools for pandemic prepared- ness in the age of climate change. My central hypothesis is that EHEs increase C-19 risk by increasing house- bound populations and promoting SARS-COV2 transmission dynamics, particularly in areas with higher pro- portions of older aged individuals, racial/ethnic minorities, and other socioeconomically disadvantaged individu- als. I will test this hypothesis by employing multivariable spatiotemporal models with quasi-experimental de- signs on several secondary data sources from the Johns Hopkins Coronavirus Resource Center (daily, nation- wide, county-level C-19 outcomes) and patient-level data from the NCATS National COVID Cohort Collabora- tive (N3C), combined with area-level socioeconomic data from the US census, and environmental data from the National Weather Service (NWS) from 2020-2022. The aims are: 1) To examine the association between EHEs and county-wide C-19 risk from a national perspective; and 2) Identify adult individual-level demo- graphic, clinical, and area-level socioeconomic characteristics associated with increased risk of C-19 related hospitalization after EHEs. This work is highly relevant to the National Institutes of Health (NIH) Strategic Framework for Climate Change and Health Initiative. In addition to supporting my pathway to independence as a translational physician-scientist, findings from this proposal will lay the foundations of future work focused on infectious disease epidemiology and climate change in a future R01 submission to the NIEHS or NIAID. 1