"Abstract
Background: This cross-sectional study aimed to track population-based SARS-CoV-2 antibody seropositivity duration across the United States using observational data from a national clinical laboratory registry of patients tested by nucleic acid amplification (NAAT) and serologic assays. Knowledge of antibody seropositivity and its duration may help dictate post-pandemic planning...
Findings: Seropositivity of IgG antibodies to both SARS-CoV-2 S and N-proteins followed a linear trend reaching approximately 90% positivity at 21 days post-index. The rate of N-protein seropositivity declined at a sharper rate, decaying to 68·2% [95% CI: 63·1–70·8%] after 293 days, while S-antibody seropositivity maintained a rate of 87·8% [95% CI: 86·3–89·1%] through 300 days. In addition to antigen type and the number of days post-positive PCR, age and gender were also significant factors in seropositivity prediction, with those under 65 years of age showing a more sustained seropositivity rate...
Discussion
... We have demonstrated a sustained positivity rate of antibodies against the SARS-CoV-2 spike protein past ten months post-PCR confirmed COVID-19 infection using data from over 39,000 patients, with linear trends indicating a substantial population half-life... This study is novel in that it provides an epidemiological view from one of the United States’ largest diagnostic laboratories, which has access to some of the most substantial longitudinal data on COVID-19."
© 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).