Influenza mortality as an indicator of the effectiveness of public health interventions and their impact on United States COVID mortality

Abstract

AbstractThe synergistic nature of non-pharmaceutical interventions (NPIs) for control of COVID makes it difficult to assess the efficacy of any individual strategy. This study uses influenza mortality reduction (IMR) during the pandemic as an indicator of the aggregate efficacy of NPIs to assess their impact on COVID mortality.Age-adjusted COVID mortality for US states were modeled as a function of four variables: mortality prior to the introduction of NPIs, vaccination rates, IMR relative to historical averages, and population density.A simple linear model with only these variables explained 69% of the state-to-state variability in age adjusted COVID mortality. The resulting model suggests that NPIs alone prevented 840,000 COVID related deaths in the United States over the course of the pandemic. These results demonstration the utility of IMRs as an indicator of the aggregate impact of NPIs for controlling transmission of respiratory infections, including COVID.