An unexpected IgE anti-receptor binding domain response following natural infection and different types of SARS-CoV-2 vaccines

• Published in: Scientific reports Vol. 14; no. 1; pp. 20003 - 12
• Main Authors: Portilho, Amanda Izeli, Silva, Valéria Oliveira, Da Costa, Hernan Hermes Monteiro, Yamashiro, Rosemeire, de Oliveira, Isabela Penteriche, de Campos, Ivana Barros, Prudencio, Carlos Roberto, Matsuda, Elaine Monteiro, de Macedo Brígido, Luís Fernando, De Gaspari, Elizabeth
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.08.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/250/255; 631/250/590; Adult; Allergies; Antibodies, Viral - immunology; Avidity; BNT162 Vaccine - immunology; Brazil; COVID-19; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 vaccine; COVID-19 vaccines; COVID-19 Vaccines - immunology; Enzyme-linked immunosorbent assay; Female; Humanities and Social Sciences; Humans; IgE; IgG4; Immune response (humoral); Immunization; Immunization, Secondary; Immunoglobulin E; Immunoglobulin E - immunology; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin G - immunology; Infections; Male; Middle Aged; mRNA; multidisciplinary; Parasites; Protein G; SARS-CoV-2; SARS-CoV-2 - immunology; Science; Science (multidisciplinary); Sepharose 4B-Protein G; Severe acute respiratory syndrome coronavirus 2; Spike Glycoprotein, Coronavirus - immunology; Vaccination; Vaccines; Young Adult; Brazil; IgG4; Avidity; COVID-19 vaccine; SARS-CoV-2; IgE; Sepharose 4B-Protein G
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-71047-5

Humoral response to SARS-CoV-2 has been studied, predominantly the classical IgG and its subclasses. Although IgE antibodies are typically specific to allergens or parasites, a few reports describe their production in response to SARS-CoV-2 and other viruses. Here, we investigated IgE specific to receptor binding domain (RBD) of SARS-CoV-2 in a Brazilian cohort following natural infection and vaccination. Samples from 59 volunteers were assessed after infection (COVID-19), primary immunization with vectored (ChAdOx1) or inactivated (CoronaVac) vaccines, and booster immunization with mRNA (BNT162b2) vaccine. Natural COVID-19 induced IgE, but vaccination increased its levels. Subjects vaccinated with two doses of ChAdOx1 exhibited a more robust response than those immunized with two doses of CoronaVac; however, after boosting with BNT162b2, all groups presented similar IgE levels. IgE showed intermediate-to-high avidity, especially after the booster vaccine. We also found IgG4 antibodies, mainly after the booster, and they moderately correlated with IgE. ELISA results were confirmed by control assays, using IgG depletion by protein G and lack of reactivity with heterologous antigen. In our cohort, no clinical data could be associated with the IgE response. We advocate for further research on IgE and its role in viral immunity, extending beyond allergies and parasitic infections.