Antibodies to coronaviruses are higher in older compared with younger adults and binding antibodies are more sensitive than neutralizing antibodies in identifying coronavirus‐associated illnesses

Abstract

Human coronaviruses (HCoV) are common causes of respiratory illnesses (RI) despite preexisting humoral immunity. Sera were obtained near the onset of RI and 3 to 4 weeks later as part of a prospective study of 200 subjects evaluated for RI from 2009 to 2013. Antibodies against common HCoV strains were measured by enzyme-linked immunosorbent assay and neutralization assay comparing older adults with cardiopulmonary diseases (99 subjects) to younger, healthy adults (101 subjects). Virus shedding was detected in respiratory secretions by polymerase chain reaction. Of 43HCoV-associated illnesses, 15 (35%) occurred in 14 older adults (aged ≥60 years) and 28 (65%) in 28 younger adults (aged 21-40 years). Binding and neutralizing antibodies were higher in older adults. Only 16 (35.7%) of RI with increases in binding antibodies also had increases in neutralizing antibodies to HCoV. Increases in binding antibodies with RI were more frequent than increased neutralizing antibodies and virus shedding, and more frequent in younger compared to older adults. Functional neutralizing antibodies were not stimulated as often as binding antibodies, explaining in part a susceptibility to reinfection with HCoV. Monitoring binding antibodies may be more sensitive for the serologic detection of HCoV infections. K E Y W O R D Santibody, coronavirus, immunity, neutralization, respiratory illness

Serological and molecular findings during SARS-CoV-2 infection: the first case study in Finland, January to February 2020

“…A meta-analysis of seroprevalence to SARS-CoV among different human populations yielded an overall low seroprevalence (0.10%), although it was slightly higher (0.23%) among healthcare workers and others who had close contact with SARS patients [20]. Binding and neutralising HCoV antibodies were found to be higher in older adults [14].…”

“…Monitoring of the binding antibodies is suggested to be a more sensitive method than measuring functional neutralising antibodies for serological detection of human coronavirus (hCoV) infections [14]. However, hCoV OC43 and 229E samples can also cross-react with SARS-CoV ELISA testing [15].…”

Immune responses and pathogenesis of SARS‐CoV‐2 during an outbreak in Iran: Comparison with SARS and MERS

“…27,28 Based on immunofluorescence assays and ELISA, in 89% of the recovered patients, IgG-specific and neutralizing antibodies were detected 2 years after SARS infection. 26,28,29 In addition, peak specific IgM on the ninth day after disease and the class switching to IgG in the second week were detected. 27,29,30 During the long-term follow-up of survivors, IgG is only detectable in recovered patients at 6 years after SARS infection, 31,32 suggesting decreasing levels of memory B-cells will also be found against SARS-CoV-2.…”

“…Humoral immune response, especially the production of neutralizing antibody, plays a protective role by limiting the infection at a later phase and prevents re-infection in the future. 26 SARS-CoV-2 infection induces IgG production against N protein that can be detected by serum as early as day 4 after the onset of disease and with most patients seroconverting by day 14. 27,28 Based on immunofluorescence assays and ELISA, in 89% of the recovered patients, IgG-specific and neutralizing antibodies were detected 2 years after SARS infection.…”

A systematic review of antibody mediated immunity to coronaviruses: antibody kinetics, correlates of protection, and association of antibody responses with severity of disease

“…A comparison of a cohort of [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] year-olds and a cohort of ≥65 year-olds found no clear difference in incidence between the two age groups, as measured by seroconversion or PCRconfirmed, HCoV-associated respiratory illness 120 . Finally, observational studies have shown evidence of coronavirus-associated respiratory illnesses in elderly populations [121][122][123] and across all ages 124 .…”