Spatiotemporal characteristics of the SARS-CoV-2 Delta wave in North Carolina

• Published in: Spatial and spatio-temporal epidemiology Vol. 45; p. 100566
• Main Authors: Pang, Cindy J., Delamater, Paul L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: B.1.617.2; COVID-19; Delta wave; SARS-CoV-2; Spatiotemporal Heterogeneity; COVID-19; Spatiotemporal Heterogeneity; SARS-CoV-2; B.1.617.2; Delta wave
• ISSN: 1877-5845; 1877-5853
• DOI: 10.1016/j.sste.2023.100566

•County-level SARS-CoV-2 immunity varied widely prior to the Delta wave.•The Delta wave varied in arrival time and magnitude across counties.•Counties with high immunity via vaccination before the Delta wave had better outcomes.•Counties with higher immunity from prior infection (pre-Delta) had worse outcomes. We constructed county-level models to examine properties of the SARS-CoV-2 B.1.617.2 (Delta) variant wave of infections in North Carolina and assessed immunity levels (via prior infection, via vaccination, and overall) prior to the Delta wave. To understand how prior immunity shaped Delta wave outcomes, we assessed relationships among these characteristics. Peak weekly infection rate and total percent of the population infected during the Delta wave were negatively correlated with the proportion of people with vaccine-derived immunity prior to the Delta Wave, signaling that places with higher vaccine uptake had better outcomes. We observed a positive correlation between immunity via infection prior to Delta and percent of the population infected during the Delta wave, meaning that counties with poor pre-Delta outcomes also had poor Delta wave outcomes. Our findings illustrate geographic variation in outcomes during the Delta wave in North Carolina, highlighting regional differences in population characteristics and infection dynamics.