Open Forum Infectious Diseases
De Thoisy A, Woudenberg T, Pelleau S, Donnadieu F, Garcia L, Pinaud L,Tondeur L, Meola A, Arowas L, Clement N, Backovic M, Ungeheuer MN, Fontanet A, White M.
Background The seasonal human coronaviruses (HCoV) NL63, 229E, OC43 and HKU1, are endemic throughout the world, yet the majority of HCoV infections remain undiagnosed. Serology can reliably identify individuals previously infected with HCoVs.
Methods In a cross-sectional seroprevalence study, 2,389 serum samples were collected from children and adults requiring hospital admission in France in 2020. In a separate longitudinal cohort study, 2,520 samples were collected from 898 individuals in a French town followed between April 2020 and December 2021. Antibodies to HCoVs were measured using a bead-based multiplex assay. Serological data from the longitudinal cohort was analyzed to estimate the rate of antibody waning. Age-stratified seroprevalence data from the cross-sectional cohort was analyzed using sero-catalytic models to estimate HCoV force of infection.
Results The rate of waning of anti-HCoV Spike IgG antibodies was estimated to be in the range 0.22–0.47 year-1 for children, and 0.13–0.27 year-1 for adults. Sero-reversion, the process where individuals become sero-negative when antibody levels wane below a sero-positivity cut-off, was estimated to occur at a rate: 0.31–1.37 year-1 in children, and 0.19–0.72 year-1 in adults. The estimated sero-conversion rate in children was in the range 0.22–0.50 year-1, equivalent to 20% – 39% of children getting infected every year with each HCoV.
Conclusions Antibodies to HCoVs in French children and adults are consistent with these viruses being at endemic equilibrium. The high force of infection in children indicates that HCoVs may be responsible for a substantial proportion of fever episodes experienced by children.
More information at doi: https://doi.org/10.1093/ofid/ofad340