Reduced seasonal coronavirus incidence in high-risk population groups during the COVID-19 pandemic

BackgroundEpidemiological data on seasonal coronaviruses (sCoVs) may provide insight on transmission patterns and demographic factors that favor coronaviruses (CoVs) with greater disease severity. This study describes the incidence of CoVs in several high-risk groups in Ottawa, Canada, from October 2020 to March 2022.MethodsSerological assays quantified IgG and IgM antibodies to SARS-CoV-2, HCoV-OC43, HCoV-NL63, HCoV-HKU1, and HCoV-229E. Incident infections were compared between four population groups: individuals exposed to children, transit users, immunocompromised, and controls. Associations between antibody prevalence indicative of natural infection and demographic variables were assessed using regression analyses.ResultsTransit users and those exposed to children were at no greater risk of infection compared to the control group. Fewer infections were detected in the immunocompromised group (p = .03). SARS-CoV-2 seroprevalence was greater in individuals with low income and within ethnic minorities.ConclusionsOur findings suggest that nonpharmaceutical interventions intended to reduce SAR-CoV-2 transmission protected populations at high risk of exposure. The re-emergence of sCoVs and other common respiratory viruses alongside SARS-CoV-2 may alter infection patterns and increase the risk in vulnerable populations. Understanding seasonal coronavirus activity may provide valuable insights into what can be anticipated of SARS-CoV-2 as we move to an endemic era. Incident seasonal coronavirus infections were found to be similar between those exposed to children, transit users and a control group while fewer natural infections were identified in immunocompromised individuals. SARS-CoV-2 seroprevalence was found to be greater in individuals with low-income and ethnic minorities using regression analyses. image