Morbidity of SARS-CoV-2 in the evolution to endemicity and in comparison with influenza

There are three possible SARS-CoV-2 post-pandemic scenarios: (i) ongoing severity, (ii) influenza-like severity, and (iii) a transition to an endemic disease with lesser morbidity similar to that of other human coronaviruses. To assess a possible evolution of the pandemic under the three scenarios, we use data from the US National Covid Cohort Collaborative, CDC COVID-NET, and CDC Fluview and from the WastewaterSCAN Dashboard. We include influenza disease and treatment response as benchmark. The US National Covid Cohort Collaborative allows the quantification of viral-specific morbidity using electronic health records from 424,165 SARS-CoV-2 cases, 53,846 influenza cases, and 199,971 uninfected control subjects from 2021–2022. Evolution of hospitalization rates is estimated from the correlation between national SARS-CoV-2 and influenza hospitalization data and viral gene copies in wastewater. Our findings reveal that medically attended SARS-CoV-2 infections exhibit similar morbidity to influenza [indicative of scenario (ii)], but SARS-CoV-2 hospitalization rates are one order of magnitude lower than influenza when considering virus concentration in wastewater [indicative of scenario (iii)]. Moreover, SARS-CoV-2 displays a more favorable response to antiviral therapy. Our analysis confirms a rapid decline in SARS-CoV-2 morbidity as it transitions to an endemic state. The impact of SARS-CoV-2 infections has changed over time since the start of the pandemic. We use information about deaths and hospitalization from COVID-19 and combine it with data obtained from monitoring wastewater to study how patterns of infection have changed over time and how this compares with the impact of influenza. We show that recently there has been a marked decrease in SARS-CoV-2 infections leading to hospitalization, in contrast to stable rates of hospitalization for people infected with influenza. Our results suggest that SARS-CoV-2 is currently a persistent, i.e., endemic disease with less severe impact on most people who are infected. This information is helpful for hospitals and public health departments that monitor and prepare for infectious disease outbreaks. Bartha et al. investigate the evolution of SARS-CoV-2 towards an endemic state. Real world data on over 600,000 individuals and from wastewater surveillance show loss of SARS-CoV-2 virulence and patterns of morbidity similar to influenza.