key: cord-1023797-1v9q4oje
authors: Francavilla, Beatrice; Nuccetelli, Marzia; Guerrieri, Mariapia; Fiorelli, Denise; Di Girolamo, Stefano
title: Importance of nasal secretions in the evaluation of mucosal immunity elicited by mRNA BNT162b2 COVID-19 Vaccine
date: 2022-04-14
journal: EBioMedicine
DOI: 10.1016/j.ebiom.2022.104006
sha: d35f495456be93465416bf15dc805cdea161f198
doc_id: 1023797
cord_uid: 1v9q4oje

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Importance of nasal secretions in the evaluation of mucosal immunity elicited by mRNA BNT162b2 COVID-19 Vaccine Beatrice Francavilla, a * Marzia Nuccetelli, b Mariapia Guerrieri, a Denise Fiorelli, b and Stefano Di Girolamo a a Department of Otorhinolaryngology, University of Rome "Tor Vergata", Rome, Italy b Department of Experimental Medicine, University of Tor Vergata, Rome, Italy Dear Editor, We read with great interest the recent publication by Azzi et al. 1 Authors analysed serum and saliva samples of subjects after mRNA COVID-19 vaccine, reporting that vaccination elicits an immune response by increasing both total and neutralising antibodies concentration in serum and in saliva. However, since antibodies levels are much higher in serum than in the salivary compartment, Authors concluded that oral mucosal immunity is poorly activated by this vaccination failing in limiting virus acquisition by mucosal routes.

Notably, results and conclusions of this study are different as compared to our recently published data and other reports, that detected significant levels of anti-SARS-CoV-2 specific IgA and IgG in saliva 2À4 and, as a novelty, in nasal secretions 5 after mRNA COVID-19 Vaccine, thus eliciting an antigen-specific mucosal immune response directly at the site of virus entry.

Probably, different procedures could have made possible the discrepancies between this paper and current literature, such as: the absence of a clear negative threshold for Anti-SARS-CoV-2 antibodies in saliva samples (since usually diagnostic kits are validated only for serum or plasma); different immunoassays methods used, and saliva collection (sputum in Azzi et al. study rather than standardized collection method such as Salivette Ò ).

Nasal immunity plays a pivotal role in the fight against COVID-19, therefore the assessment of specific antibodies in nasal secretions is determinant in the study of mucosal immunity elicited by Anti-SARS-CoV-2 vaccine. Further studies are needed to consolidate results and to longitudinally evaluate the persistence of both nasal and salivary antibodies.

Mucosal immune response in BNT162b2 COVID-19 vaccine recipients

Antibody responses to SARS-CoV-2 mRNA vaccines are detectable in saliva

Immune response to SARS-CoV-2 variants of concern in vaccinated individuals

SARS-CoV-2 antibodies are persisting in saliva for more than 15 months after infection and become strongly boosted after vaccination

Nasal and salivary mucosal humoral immune response elicited by mRNA BNT162b2 COVID-19 vaccine compared to SARS-CoV-2 natural infection. Vaccines

All authors have contributed equally to this letter.

All authors disclose no financial and personal relationships with other people or organizations that could inappropriately influence their work.