The COVID-19 pandemic has highlighted the importance of understanding the immune response to seasonal human coronavirus (HCoV) infections such as HCoV-NL63, how existing neutralising antibodies to HCoV may modulate responses to SARS-CoV-2 infection, and the utility of seasonal HCoV as human challenge models. Therefore, in this study we quantified HCoV-NL63 neutralising antibody titres in a healthy adult population using plasma from 100 blood donors in Australia. A microneutralisation assay was performed with plasma diluted from 1:10 to 1:160 and tested with the HCoV-NL63 Amsterdam-1 strain. Neutralising antibodies were detected in 71% of the plasma samples, with a median geometric mean titre of 14. This titre was similar to those reported in convalescent sera taken from individuals 3–7 months following asymptomatic SARS-CoV-2 infection, and 2–3 years post-infection from symptomatic SARS-CoV-1 patients. HCoV-NL63 neutralising antibody titres decreased with increasing age (R 2 = 0.042, p = 0.038), but did not differ by sex. Overall, this study demonstrates that neutralising antibody to HCoV-NL63 is detectable in approximately 71% of the healthy adult population of Australia. Similar titres did not impede the use of another seasonal human coronavirus (HCoV-229E) in a human challenge model, thus, HCoV-NL63 may be useful as a human challenge model for more pathogenic coronaviruses.
【저자키워드】 HCoV-NL63, neutralising antibody titre, healthy adults, 【초록키워드】 coronavirus, immune response, antibody, SARS-COV-2 infection, COVID-19 pandemic, Infection, Sex, Asymptomatic, symptomatic, neutralising antibody, response, HCoV-229E, plasma, utility, convalescent sera, blood donor, Post-infection, individual, plasma samples, titre, increasing age, pathogenic coronaviruses, microneutralisation assay, geometric mean titre, not differ, tested, healthy, reported, detectable, was performed, median, modulate, R 2, quantified, SARS-CoV-1 patients, the healthy,