Review
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Virol. Sep 25, 2022; 11(5): 221-236
Published online Sep 25, 2022. doi: 10.5501/wjv.v11.i5.221
Mucosal COVID-19 vaccines: Risks, benefits and control of the pandemic
Dimitrina Miteva, Monika Peshevska-Sekulovska, Violeta Snegarova, Hristiana Batselova, Radostina Alexandrova, Tsvetelina Velikova
Dimitrina Miteva, Department of Genetics, Sofia University “St. Kliment Ohridski,” Faculty of Biology, Sofia 1164, Bulgaria
Monika Peshevska-Sekulovska, Department of Gastroenterology, University Hospital Lozenetz, Sofia 1407, Bulgaria
Monika Peshevska-Sekulovska, Tsvetelina Velikova, Medical Faculty, Sofia University St. Kliment Ohridski, Sofia 1407, Bulgaria
Violeta Snegarova, Clinic of Internal Diseases, Naval Hospital - Varna, Military Medical Academy, Medical Faculty, Medical University, Varna 9000, Bulgaria
Hristiana Batselova, Department of Epidemiology and Disaster Medicine, Medical University, Plovdiv, University Hospital “St George”, Plovdiv 6000, Bulgaria
Radostina Alexandrova, Department of Pathology, Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia 1000, Bulgaria
Tsvetelina Velikova, Department of Clinical Immunology, University Hospital Lozenetz, Sofia 1407, Bulgaria
Author contributions: Miteva D and Velikova T were involved in conceptualizing the idea and writing the draft; Peshevska-Sekulovska M, Snegarova V and Batselova H wrote additional sections in the paper; Velikova T crafted the figure; Alexandrova R was responsible for the critical revision of the manuscript for relevant intellectual content; All of the authors approved the final version of the paper prior to submission.
Conflict-of-interest statement: All the authors declare no conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Tsvetelina Velikova, MD, PhD, Assistant Professor, Department of Clinical Immunology, University Hospital Lozenetz, Kozyak 1 Street, Sofia 1407, Bulgaria. tsvelikova@medfac.mu-sofia.bg
Received: March 13, 2022
Peer-review started: March 13, 2022
First decision: April 8, 2022
Revised: May 14, 2022
Accepted: August 10, 2022
Article in press: August 10, 2022
Published online: September 25, 2022
Processing time: 195 Days and 10.2 Hours
Abstract

Based on mucosal immunization to promote both mucosal and systemic immune responses, next-generation coronavirus disease 2019 (COVID-19) vaccines would be administered intranasally or orally. The goal of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is to provide adequate immune protection and avoid severe disease and death. Mucosal vaccine candidates for COVID-19 including vector vaccines, recombinant subunit vaccines and live attenuated vaccines are under development. Furthermore, subunit protein vac-cines and virus-vectored vaccines have made substantial progress in preclinical and clinical settings, resulting in SARS-CoV-2 intranasal vaccines based on the previously successfully used nasal vaccines. Additional to their ability to trigger stable, protective immune responses at the sites of pathogenic infection, the development of ‘specific’ mucosal vaccines targeting coronavirus antigens could be an excellent option for preventing future pandemics. However, their efficacy and safety should be confirmed.

Keywords: SARS-CoV-2; COVID-19 vaccine; Mucosal immunity; Intranasal vaccination; Oral vaccines; Resident memory T cells; Vaccine safety; Vaxart; OraPro-COVID-19 vaccine; RPS-vector system platform

Core Tip: Oral or nasal vaccination against coronavirus disease 2019 (COVID-19) would stimulate both the humoral and cellular immune responses and may exert many socioeconomic benefits. Mucosal vaccines are promising for preventing infections and reducing the transmission, morbidity and mortality of COVID-19. Mucosal vaccination may be used prophylactically in human populations at high risk for severe acute respiratory syndrome coronavirus 2. Currently, only a limited number of oral vaccines are approved for human use, and some others are included in preclinical and clinical trials to validate their efficacy and safety.