Sequential Analysis of Binding and Neutralizing Antibody in COVID-19 Convalescent Patients at 14 Months After SARS-CoV-2 Infection

Abstract

Durability of SARS-CoV-2 Spike antibody responses after infection provides information relevant to understanding protection against COVID-19 in humans. We report the results of a sequential evaluation of anti-SARS-CoV-2 antibodies in convalescent patients with a median follow-up of 14 months (range 12.4-15.4) post first symptom onset. We report persistence of antibodies for all four specificities tested [Spike, Spike Receptor Binding Domain (Spike-RBD), Nucleocapsid, Nucleocapsid RNA Binding Domain (N-RBD)]. Anti-Spike antibodies persist better than anti-Nucleocapsid antibodies. The durability analysis supports a bi-phasic antibody decay with longer half-lives of antibodies after 6 months and antibody persistence for up to 14 months. Patients infected with the Wuhan (WA1) strain maintained strong cross-reactive recognition of Alpha and Delta Spike-RBD but significantly reduced binding to Beta and Mu Spike-RBD. Sixty percent of convalescent patients with detectable WA1-specific NAb also showed strong neutralization of the Delta variant, the prevalent strain of the present pandemic. These data show that convalescent patients maintain functional antibody responses for more than one year after infection, suggesting a strong long-lasting response after symptomatic disease that may offer a prolonged protection against re-infection. One patient from this cohort showed strong increase of both Spike and Nucleocapsid antibodies at 14 months post-infection indicating SARS-CoV-2 re-exposure. These antibodies showed stronger cross-reactivity to a panel of Spike-RBD including Beta, Delta and Mu and neutralization of a panel of Spike variants including Beta and Gamma. This patient provides an example of strong anti-Spike recall immunity able to control infection at an asymptomatic level. Together, the antibodies from SARS-CoV-2 convalescent patients persist over 14 months and continue to maintain cross-reactivity to the current variants of concern and show strong functional properties.

ChAdOx1 nCoV-19 Immunogenicity and Immunological Response Following COVID-19 Infection in Patients Receiving Maintenance Hemodialysis

“…Similar to the findings in ESRD patients with HD after COVID-19 infection, the results in the general population on the dynamics of IgG levels post-COVID-19 infection were inconclusive. Some studies in the general population reported a substantial decline in IgG [54] and neutralizing antibody over 3 months postinfection [55], yet other studies showed a stable antibody level after 6 [56][57][58] to 12 months post-infection [59]. Interestingly, the dynamics of IgG levels following infection in our study were similar to those in ESRD patients with kidney transplantation, who had significant IgG persistence over 3 months after COVID-19 infection [60].…”

Reduced Antibodies and Innate Cytokine Changes in SARS-CoV-2 BNT162b2 mRNA Vaccinated Transplant Patients With Hematological Malignancies

“…In-house ELISA assays using a panel of purified trimeric complete Wuhan strain (WA1) Spike and Spike-RBD and a panel of VOC Spike-RBD proteins (Beta B.1.351, Delta B.1.617.2, Omicron B.1.1.529) were detailed elsewhere ( 26 – 28 ). Ab levels were measured using eight 4-fold serial serum dilutions starting at 1:50 and endpoint titers were determined using lastX feature using GraphPad prism area-under-the curve program.…”

SARS-CoV-2 reinfections: Overview of efficacy and duration of natural and hybrid immunity

“…Taken together, epidemiological studies indicate that protection against reinfections by natural immunity lasts for over one year with only moderate, if at all, decline over this period. The notion of long-term protection against-reinfections is also underpinned by data on persistance of anti SARS-CoV-2 antibodies and cellular immunity over more than one year in the majority of patients ( Chellamuthu et al, 2021 ; Dehgani-Mobaraki et al, 2021 ; Gussarow et al, 2021 ; Lau et al, 2021 ; Rosati et al, 2021 ).…”