The long-term dynamics of serum antibodies against SARS-CoV-2

PeerJ. 2022 Dec 15:10:e14547. doi: 10.7717/peerj.14547. eCollection 2022.

Abstract

Objective: To analyze the long-term dynamics of antibodies against SARS-CoV-2 and understand the impact of age, gender, and viral load on patients' immunological response.

Methods: Serum samples were obtained from 231 COVID-19 positive patients from Macaé, in Rio de Janeiro state, in Brazil, from June 2020 until January 2021. The production of IgA, IgM, IgG, and IgE against S glycoprotein was analyzed using the S-UFRJ assay, taking into account the age, gender, and viral load.

Results: Analysis of antibody production over 7 months revealed that IgA positivity gradually decreased after the first month. Additionally, the highest percentage of IgM positivity occurred in the first month (97% of patients), and declined after this period, while IgG positivity remained homogeneous for all 7 months. The same analysis for IgE revealed that almost all samples were negative. The comparison of antibody production between genders showed no significant difference. Regarding the age factor and antibody production, patients aged ≥60 years produced almost twice more IgA than younger ones (17-39 years old). Finally, a relationship between viral load and antibody production was observed only for older patients.

Conclusions: Our work provides an overview of long-term production of antibodies against SARS-CoV-2, suggesting prolonged production of IgA and IgM antibodies for 3 months and continued IgG production for over 7 months. In addition, it identified a correlation between viral load and IgM titers in the older group and, finally, different IgA production between the age groups.

Keywords: Age; Antibody production; COVID-19 patients; Gender; Immune responses; S-UFRJ; SARS-CoV-2-specific antibodies; Seroconversion; Serologic response; Spike glycoprotein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Viral
  • Brazil / epidemiology
  • COVID-19*
  • Female
  • Humans
  • Immunoglobulin A
  • Immunoglobulin E
  • Immunoglobulin G
  • Immunoglobulin M
  • Male
  • SARS-CoV-2*
  • Young Adult

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M
  • Immunoglobulin A
  • Immunoglobulin E

Grants and funding

This research was supported by the Justiça Federal de Macaé (JFM), the Justiça Federal de Itaperuna (JFI), and the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), through grant numbers E-26/210.176/2020/ and E-26/210.822/2021. The Institute of Biodiversity and Sustainability (NUPEM) of the Federal University of Rio de Janeiro (UFRJ) received support from the Ministério Público Federal, the Ministério Público do Trabalho, the Confederação Nacional das Cooperativas Médicas (UNIMED), Irmandade São João Batista, the Prefeitura Municipal de Macaé, the Tribunal Regional Federal da 4ª Região (TRF-4), the Associação dos Docentes da UFRJ (ADUFRJ), and donors that contributed to this research. The complete list of donors is available at http://transparencia.coppetec.ufrj.br/pesquisa-covid19-macae.php. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.