Figure 1. Matched case–control pairs used in the conditional logistic regression by analysis for the SARS-CoV-2 Delta variant (March 19, 2021–August 15, 2021) and the Omicron variant (November 28, 2021–January 24, 2022) emergence periods, by economic region (map), New York, USA. The bars correspond to the order given in the legend; New York City is on top when present and Long Island on bottom when present. The dashed line separates the 2 datasets used in the analyses; the Delta emergence period is on the left and the Omicron emergence period on the right. Map base layer was derived from a combination of 2 public domain layers (US Census data, https://www.census.gov/geo/maps-data/data/tiger-line.html) and Natural Earth Administrative boundaries (https://www.naturalearthdata.com/downloads/50m-cultural-vectors/50m-admin-1-states-provinces).