Long-term systemic and mucosal SARS-CoV-2 IgA response and its association with persistent smell and taste disorders

Jessica Denis (1) , Annabelle Garnier (1) , Laurence Cheutin (1) , Audrey Ferrier (1) , Hawa Timera (1) , Fanny Jarjaval (1) , Carine Hejl (2, 3) , Emmanuelle Billon-Denis (1) , Percy Immunocovid Group , Damien Ricard (2, 3, 4) , Jean-Nicolas Tournier (1, 3) , Aurélie Trignol (1, 5) , Marie Mura (1, 6)

1 IRBA - Institut de Recherche Biomédicale des Armées [Brétigny-sur-Orge]
2 Hôpital d'instruction des Armées Percy
3 EVDG - École du Val de Grâce
4 CB - CB - Centre Borelli - UMR 9010
5 VIFASOM (URP_7330) - Sommeil-Vigilance-Fatigue et Santé Publique
6 Laboratoire d’innovation : vaccins – Innovation lab : vaccines

Introduction: Current approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission. Methods: We measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer). Results: While serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19. Discussion: As breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders.

Mots clés: mucosal immunity; SARS-CoV2 vaccine; dysosmia; dysgeusia; IgA; Spike N-terminal domain; smell; taste

Domaines: Sciences du Vivant [q-bio]

Jessica Denis, Annabelle Garnier, Laurence Cheutin, Audrey Ferrier, Hawa Timera, et al.. Long-term systemic and mucosal SARS-CoV-2 IgA response and its association with persistent smell and taste disorders. Frontiers in Immunology, 2023, 14, pp.1140714. ⟨10.3389/fimmu.2023.1140714⟩. ⟨hal-04503922⟩