Prevalence of IgG Antibodies to SARS-CoV-2 in Wuhan – Implications for the Longevity of Antibodies Against SARS-CoV-2

Abstract Background It is to be determined whether people infected with SARS-CoV-2 will develop long-term immunity against SARS-CoV-2 and retain long-lasting antibodies after the infection is resolved. This study was to explore the outcomes of IgG antibodies to SARS-CoV-2 in four groups of individuals in Wuhan, China.MethodsWe conducted a cross-sectional study on the following four groups who received both COVID-19 IgM/IgG tests and RT-PCR tests for SARS-CoV-2 from February 29, 2020 to April 29, 2020: 1470 hospitalized patients with COVID-19 from Leishenshan Hospital, Zhongnan Hospital of Wuhan University, and Wuhan No. 7 Hospital, 3832 healthcare providers without COVID-19 diagnosis, 19555 general workers, and 1616 other patients to be admitted to the hospital (N=26473). COVID-19 patients who received IgM/IgG tests <21 days after symptom onset were excluded. Results IgG prevalence was 89.8% (95% CI 88.2-91.3%) in COVID-19 patients, 4.0% (95% CI 3.4-4.7%) in healthcare providers, 4.6 (95% CI 4.3-4.9 %) in general workers, and 1.0% in other patients (p all <0.001 for comparisons with COVID-19 patients). IgG prevalence increased significantly by age among healthcare workers and general workers. Among hospitalized COVID-19 patients, presence of IgG antibodies to SARS-CoV-2 was not associated with most disease severity, presence of comorbidities, treatment received, and clinical characteristics. We identified 24 hospitalized patients with COVID-19 and multiple COVID-19 antibody tests who lost previously detected IgG antibodies to SARS-CoV-2ConclusionsIgG antibodies to SARS-CoV-2 in infected people may become undetectable overtime.