Longitudinal observation of antibody responses for 14 months after SARS-CoV-2 infection

Abstract

\n Better understanding of antibody responses against SARS-CoV-2 after natural infection might provide valuable insights into the future implementation of vaccination policies.Longitudinal analysis of IgG antibody titers was carried out in 32 recovered COVID-19 patients based in the Umbria region of Italy for 14\u202fmonths after Mild and Moderately-Severe infection.Two FDA-approved immunoassays against SARS-CoV-2 Nucleocapsid protein(NCP) and anti-spike-receptor binding domain(S-RBD) were used for sequential serological tests at different time points.The demographics,clinical history and symptom profile associated with the magnitude and longevity of antibody responses were also analyzed.Anti-S-RBD IgG persisted in 96.8% (31 of 32) subjects at 14\u202fmonths.Patients reporting loss of smell and taste during the clinical course of the disease developed significantly higher antibody titers.Anti-NCP IgG seronegative patients(n\u202f=\u202f7) at 10\u202fmonths,tested positive for anti-S-RBD IgG at 12,13 and 14\u202fmonths emphasizing on a higher false-negative rate for NCP protein-based antibody assays.This study also highlights the importance of adopting specific immunoassays for routine estimation of antibody titers and the decreased rate of re-infections in recovered patients.\n