Reduced seasonal coronavirus incidence in high-risk population groups
during the COVID-19 pandemic
Abstract
Background: Epidemiological data on seasonal coronaviruses (sCoVs) may
provide insight on transmission patterns and demographic factors that
favour 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. Methods: Serological 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. Results: Transit 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=0.03). SARS-CoV-2 seroprevalence was greater
in individuals with low income and within ethnic minorities.
Conclusions: Our findings suggest that non-pharmaceutical 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.