Detection of anti-SARS-CoV-2 salivary antibodies in vaccinated adults

Front Immunol. 2023 Nov 7:14:1296603. doi: 10.3389/fimmu.2023.1296603. eCollection 2023.

Abstract

Since the introduction of efficient anti-SARS-CoV-2 vaccines, the detection of antibodies becomes useful for immunological monitoring and COVID-19 control. Therefore, this longitudinal study aimed to evaluate the detection of SARS-CoV-2 antibodies in the serum and saliva of COVID-19-vaccinated adults. The study included 13 not vaccinated and 35 vaccinated participants with two doses of CoronaVac (Sinovac/Butantan) vaccine who subsequently received BNT162b2 (Pfizer-BioNTech) vaccine as a booster dose. Vaccinated participants donated saliva and serum in three different time points. Enzyme-linked immunosorbent assay was used for antibody detection. In our results, the serum neutralizing antibodies (NAb) were detected in 34/35 samples after second dose and in 35/35 samples one and five months after the booster dose. In saliva, NAb were detected in 30/35 samples after second dose and in 35/35 of samples one and five months after the booster dose. IgA was detected in 19/34 saliva samples after second dose, in 18/35 one month after the booster and in 30/35 five months after. IgG in saliva was detected in 1/34 samples after second dose, 33/35 samples one month after the booster dose and in 20/35 five months after. A strong correlation was found between IgG and neutralizing activity in saliva, and salivary IgA would be a sign of recent exposure to the virus. In conclusion, saliva can be suitable for monitoring antibodies anti-SARS-CoV-2 after vaccination. Heterologous vaccination contributed to increase anti-SARS-CoV-2 antibodies in the Brazilian health context. Complementary studies with large groups are mandatory to conclude the interest in following mucosal immunity.

Keywords: COVID-19; COVID-19 vaccines; IgA; IgG; SARS-CoV-2; antibodies; neutralizing antibodies; saliva.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • BNT162 Vaccine*
  • COVID-19* / prevention & control
  • Humans
  • Immunoglobulin A
  • Immunoglobulin G
  • Longitudinal Studies
  • SARS-CoV-2

Substances

  • sinovac COVID-19 vaccine
  • BNT162 Vaccine
  • Antibodies, Viral
  • Antibodies, Neutralizing
  • Immunoglobulin A
  • Immunoglobulin G

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. VC and JA are supported by CAPES — Coordination for the Improvement of Higher Education Personnel, Brazil. EG are supported by the National Council for Scientific and Technological Development (CNPq, Ministry of Education, Brazil). This research was financially supported by the Foundation of Research Assistance of the Federal District (FAPDF) (EDITAL FAPDF 04/2021-Demanda Espontânea – 00193-00001145/2021-12), and had the collaboration DPI, University of Brasilia (UnB), and the support of the Nucleus of Support on Research (Nucleo de Apoio a Pesquisa-NAP) from the Sabin Institute and SABIN Medicina Diagnóstica for performing the laboratory tests.