Cross-sectional Characterization of SARS-CoV-2 Antibody Levels and Decay Rates Following Infection of Unvaccinated Elderly Individuals

Whelan, Marilyn; Galipeau, Yannick; White-Al Habeeb, Nicole; Konforte, Danijela; Abou El Hassan, Mohamed; Booth, Ronald A.; Arnold, Corey; Langlois, Marc-André; Pelchat, Martin

Cross-sectional Characterization of SARS-CoV-2 Antibody Levels and Decay Rates Following Infection of Unvaccinated Elderly Individuals

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creativework.keywords - en: COVID-19; elderly; neutralization; SARS-CoV-2; serology
dc.contributor.author: Whelan, Marilyn; Galipeau, Yannick; White-Al Habeeb, Nicole; Konforte, Danijela; Abou El Hassan, Mohamed; Booth, Ronald A.; Arnold, Corey; Langlois, Marc-André; Pelchat, Martin
dc.date.accepted: 2023-07-19
dc.date.accessioned: 2024-01-03T19:18:41Z
dc.date.available: 2024-01-03T19:18:41Z
dc.date.issued: 2023-07-20
dc.date.submitted: 2023-05-02
dc.description.abstract - en: BACKGROUND SARS-CoV-2 infections have disproportionally burdened elderly populations with excessive mortality. While several contributing factors exists, questions remain about the quality and duration of humoral antibody–mediated responses resulting from infections in unvaccinated elderly individuals. METHODS Residual serum/plasma samples were collected from individuals undergoing routine SARS-CoV-2 polymerase chain reaction testing in a community laboratory in Canada. The samples were collected in 2020, before vaccines became available. IgG, IgA, and IgM antibodies against SARS-CoV-2 nucleocapsid, trimeric spike, and its receptor-binding domain were quantified via a high-throughput chemiluminescent enzyme-linked immunosorbent assay. Neutralization efficiency was also quantified through a surrogate high-throughput protein–based neutralization assay. RESULTS This study analyzed SARS-CoV-2 antibody levels in a large cross-sectional cohort (N = 739), enriched for elderly individuals (median age, 82 years; 75% >65 years old), where 72% of samples tested positive for SARS-CoV-2 by polymerase chain reaction. The age group ≥90 years had higher levels of antibodies than that <65 years. Neutralization efficiency showed an age-dependent trend, where older persons had higher levels of neutralizing antibodies. Antibodies targeting the nucleocapsid had the fastest decline. IgG antibodies targeting the receptor-binding domain remained stable over time, potentially explaining the lack of neutralization decay observed in this cohort. CONCLUSIONS Despite older individuals having the highest levels of antibodies postinfection, they are the cohort in which antibody decay was the fastest. Until a better understanding of correlates of protection is acquired, along with the protective role of nonneutralizing antibodies, booster vaccinations remain important in this demographic.
dc.identifier.citation: Marilyn Whelan, Yannick Galipeau, Nicole White-Al Habeeb, Danijela Konforte, Mohamed Abou El Hassan, Ronald A Booth, Corey Arnold, Marc-André Langlois, Martin Pelchat, Cross-sectional Characterization of SARS-CoV-2 Antibody Levels and Decay Rates Following Infection of Unvaccinated Elderly Individuals, Open Forum Infectious Diseases, Volume 10, Issue 8, August 2023, ofad384, https://doi.org/10.1093/ofid/ofad384
dc.identifier.doi: https://doi.org/10.1093/ofid/ofad384
dc.identifier.issn: 2328-8957
dc.identifier.uri: https://open-science.canada.ca/handle/123456789/1399
dc.language.iso: en
dc.publisher: Oxford University Press
dc.rights - en: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
dc.rights - fr: Creative Commons Attribution - Pas d'utilisation commerciale - Pas de modification 4.0 International (CC BY-NC-ND 4.0)
dc.rights.openaccesslevel - en: Gold
dc.rights.openaccesslevel - fr: Or
dc.rights.uri - en: https://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rights.uri - fr: https://creativecommons.org/licenses/by-nc-nd/4.0/deed.fr
dc.subject - en: Health
dc.subject - fr: Santé
dc.subject.en - en: Health
dc.subject.fr - fr: Santé
dc.title - en: Cross-sectional Characterization of SARS-CoV-2 Antibody Levels and Decay Rates Following Infection of Unvaccinated Elderly Individuals
dc.type - en: Article
dc.type - fr: Article
local.article.journalissue: 8
local.article.journaltitle: Open Forum Infectious Diseases
local.article.journalvolume: 10
local.peerreview - en: Yes
local.peerreview - fr: Oui