The mRNA-1273 Vaccine Induces Cross-Variant Antibody Responses to SARS-CoV-2 With Distinct Profiles in Individuals With or Without Pre-Existing Immunity

• Published in: Frontiers in immunology Vol. 12; p. 737083
• Main Authors: Tejedor Vaquero, Sonia, de Campos-Mata, Leire, Ramada, José María, Díaz, Pilar, Navarro-Barriuso, Juan, Ribas-Llaurado, Clara, Rodrigo Melero, Natalia, Carolis, Carlo, Cerutti, Andrea, Gimeno, Ramon, Magri, Giuliana
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 03.09.2021
• Subjects: 2019-nCoV Vaccine mRNA-1273; Adult; Antibodies, Neutralizing - blood; Antibodies, Neutralizing - immunology; Antibodies, Viral - blood; Antibodies, Viral - immunology; antibody subclasses; Convalescence; COVID-19; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 Vaccines - immunology; Female; Humans; humoral immunity; Immunoglobulin A - blood; Immunoglobulin G - blood; Immunoglobulin G - immunology; Immunoglobulin M - blood; Immunology; Longitudinal Studies; Male; mRNA vaccination; SARS-CoV-2 - immunology; Spain; Spike Glycoprotein, Coronavirus - immunology; Vaccination; variants of concern; Spain; COVID-19; humoral immunity; antibody subclasses; variants of concern; mRNA vaccination
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.737083

mRNA-based vaccines effectively induce protective neutralizing antibodies against SARS-CoV-2, the etiological agent of COVID-19. Yet, the kinetics and compositional patterns of vaccine-induced antibody responses to the original strain and emerging variants of concern remain largely unknown. Here we characterized serum antibody classes and subclasses targeting the spike receptor-binding domain of SARS-CoV-2 wild type and α, β, γ and δ variants in a longitudinal cohort of SARS-CoV-2 naïve and COVID-19 recovered individuals receiving the mRNA-1273 vaccine. We found that mRNA-1273 vaccine recipients developed a SARS-CoV-2-specific antibody response with a subclass profile comparable to that induced by natural infection. Importantly, these antibody responses targeted both wild type SARS-CoV-2 as well as its α, β, γ and δ variants. Following primary vaccination, individuals with pre-existing immunity showed higher induction of all antibodies but IgG3 compared to SARS-CoV-2-naïve subjects. Unlike naïve individuals, COVID-19 recovered subjects did not mount a recall antibody response upon the second vaccine dose. In these individuals, secondary immunization resulted in a slight reduction of IgG1 against the receptor-binding domain of β and γ variants. Despite the lack of recall humoral response, vaccinees with pre-existing immunity still showed higher titers of IgG1 and IgA to all variants analyzed compared to fully vaccinated naïve individuals. Our findings indicate that mRNA-1273 vaccine triggered cross-variant antibody responses with distinct profiles in vaccinees with or without pre-existing immunity and suggest that individuals with prior history of SARS-CoV-2 infection may not benefit from the second mRNA vaccine dose with the current standard regimen.