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SARS-CoV-2 Vaccination: What Can We Expect Now?

INRAE, Oniris, BIOEPAR, 44300 Nantes, France
Department of Veterinary Microbiology and Immunology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
Department of Microbiology & Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697, USA
College Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
Author to whom correspondence should be addressed.
Vaccines 2022, 10(7), 1093;
Submission received: 21 June 2022 / Revised: 21 June 2022 / Accepted: 27 June 2022 / Published: 8 July 2022
At the beginning of summer 2022, my colleagues and I wanted to share some thoughts about a vaccination success story, i.e., the first messenger RNA (mRNA) vaccines against coronavirus disease 2019’s (COVID-19) [1,2]. Indeed, after a one-year vaccination campaign taking place in almost every country, the time has come to think about what we could see next in the future for vaccination and research against this viral disease.
Never has a vaccine been successfully developed so quickly against an emerging disease [3,4]. Billions of people have been vaccinated against COVID-19 using mRNA vaccines and more conventional approaches [5]. However, there is still room for improvement regarding the vaccines and the public acceptance of the injections in the human populations in its all diversity. First, because of the fast-evolving nature of coronavirus genomes and the continuous emergence of new variants, close monitoring of vaccine effectiveness and the development of upgraded versions of the vaccines able to control the new mutations are needed [6,7,8]. Recently, Moderna announced promising results for mRNA-1273.214 eliciting immunity against the Omicron variant [9], and there is no doubt other companies will follow up soon with updated versions of their vaccines. Additionally, mucosal vaccination and the development of vaccines that can be delivered through nasal and oral routes are progressing. Currently, there are two ongoing trials assessing parenteral–mucosal strategies for SARS-CoV-2 vaccination using spike and nucleocapsid proteins: NCT04732468 and IG/VPIN/CVD19/2001 [10]. Furthermore, in France, the development of a candidate vaccine that could be administered nasally [11] is progressing well and in July 2023 a phase I/IIa study will be started to evaluate its safety, tolerability, and immunogenicity. The ability of mucosal vaccines to elicit an early antiviral response preventing systemic circulation of viral particles could be a breakthrough in the fight against the virus and could have a significantly greater impact on SARS-CoV-2 infections than the current vaccines. This new generation of vaccines could also be more easily accepted by the general population than the parenteral vaccines for which the fear of injection remains significant. The determinants of vaccine hesitancy have been analyzed in many studies in different contexts and in various situations in our journal in recent months [12,13,14,15,16,17,18]. A deep understanding of these hesitancy determinants and how we can act on them would definitely contribute to increasing vaccination coverage in the general population. This increase is crucial, especially for fragile populations and for immunocompromised individuals.
Another challenge in the field of COVID research is to decipher all the aspects of the immune response developed after vaccination, especially the cellular immune response [19] which still remains more challenging to monitor than its humoral counterpart. However, recent progress has been made, and humoral as well as cellular immune responses to the four main anti-COVID-19 vaccines have gained a more complete understanding [20,21,22]. More specifically, in a recent study [20] it was shown that the mRNA vaccines were the most immunogenic for all the antigen-specific immune metrics analyzed. The mRNA vaccines were associated with significant declines in the neutralizing antibody titers in the initial 6 months following vaccination, while memory CD4+ and CD8+ T cells exhibited small reductions and memory B cells showed small increases [20]. In addition to this progress in our understanding of the immune responses developed after vaccinations as well as following natural infections, many questions remain unanswered. There is still much to discover about long COVID [23] and the complex and various interactions between SARS-CoV-2 and all its target cells requires more research. There is no doubt the coming years will bring exciting new findings regarding SARS-CoV-2 pathophysiology.
SARS-CoV-2 is more and more frequently directly or indirectly detected in different animal species, and many reports have shown its capacity to productively infect various animal species including the white-tailed deer (Odocoileus virginianus) [24,25] and the American mink (Neovison vison) [26]. The potential development of animal reservoirs and the risk of re-emergences, and even of emergences of significantly mutated strains, could suggest at some point a need to vaccinate some animal species against SARS-CoV-2 (and/or related viruses). Most of the emerging pathogens come from animal species [27,28,29], and a close monitoring of these species, with possibly one health prophylactic or therapeutic intervention [29], is required, ideally before the emergence itself. Thus, vaccination against SARS-CoV-2 and more generally against coronaviruses in animals has a promising future. In humans, a second generation of vaccines against COVID-19 is coming, and in June 2022 the pediatric version of the anti-COVID-19 vaccine has been approved for children in the USA [30]. Age-specific [30] and medical condition-specific vaccination procedures and formulations [31,32,33,34,35,36,37,38,39] definitely constitute a new paradigm in the “vaccine world”. Major developments are expected in the near future. Indeed, mRNA vaccines are fantastic tools to manage the COVID crisis [20]. However, these tools can be further improved to decrease supply logistics issues and to generate longer and more universal immune responses. Self-amplifying mRNA and new delivery platforms, for instance, are in the pipeline, along with mucosal vaccine candidates, to provide populations with new generations of vaccines against SARS-CoV-2 infections and COVID-19 disease.
To conclude, the COVID-19 crisis has been impressive and inspiring for immuno-virology and vaccine development with the official beginning of an mRNA vaccine era for mass vaccination. After a one-year battle, the virus spread is still not fully controlled, and the virus has not yet been defeated. Many challenges still need to be addressed by scientists and health specialists. Moreover, disparities and inequalities between countries are still significant barriers to disease control, underscoring the urgent need for reliable, efficient, and affordable COVID-19 vaccines in many countries.


F.M. was supported by an establishment grant from the Région Pays de la Loire (RFI Food for tomorrow-Cap aliment).


We thank Pr Ian Nicholson (Oniris) and Pr Bert Semler (University of California) for their careful revision of the manuscript.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Jackson, L.A.; Anderson, E.J.; Rouphael, N.G.; Roberts, P.C.; Makhene, M.; Coler, R.N.; McCullough, M.P.; Chappell, J.D.; Denison, M.R.; Stevens, L.J.; et al. An MRNA Vaccine against SARS-CoV-2—Preliminary Report. N. Engl. J. Med. 2020, 383, 1920–1931. [Google Scholar] [CrossRef] [PubMed]
  2. Anderson, E.J.; Rouphael, N.G.; Widge, A.T.; Jackson, L.A.; Roberts, P.C.; Makhene, M.; Chappell, J.D.; Denison, M.R.; Stevens, L.J.; Pruijssers, A.J.; et al. Safety and Immunogenicity of SARS-CoV-2 MRNA-1273 Vaccine in Older Adults. N. Engl. J. Med. 2020, 383, 2427–2438. [Google Scholar] [CrossRef] [PubMed]
  3. Dolgin, E. The Tangled History of MRNA Vaccines. Nature 2021, 597, 318–324. [Google Scholar] [CrossRef] [PubMed]
  4. Plotkin, S. History of Vaccination. Proc. Natl. Acad. Sci. USA 2014, 111, 12283–12287. [Google Scholar] [CrossRef] [Green Version]
  5. Tregoning, J.S.; Flight, K.E.; Higham, S.L.; Wang, Z.; Pierce, B.F. Progress of the COVID-19 Vaccine Effort: Viruses, Vaccines and Variants versus Efficacy, Effectiveness and Escape. Nat. Rev. Immunol. 2021, 21, 626–636. [Google Scholar] [CrossRef]
  6. Stefanelli, P.; Rezza, G. COVID-19 Vaccination Strategies and Their Adaptation to the Emergence of SARS-CoV-2 Variants. Vaccines 2022, 10, 905. [Google Scholar] [CrossRef]
  7. Rubin, R. Challenges of Deciding Whether and How to Update COVID-19 Vaccines to Protect Against Variants | Vaccination | JAMA | JAMA Network. Available online: (accessed on 19 June 2022).
  8. Zhang, Y.; Tan, W.; Lou, Z.; Huang, B.; Zhou, W.; Zhao, Y.; Zhang, J.; Liang, H.; Li, N.; Zhu, X.; et al. Immunogenicity Evaluating of the Multivalent COVID-19 Inactivated Vaccine against the SARS-CoV-2 Variants. Vaccines 2022, 10, 956. [Google Scholar] [CrossRef]
  9. Moderna Moderna Announces Omicron-Containing Bivalent Booster Candidate MRNA-1273.214 Demonstrates Superior Antibody Response Against Omicron. Available online: (accessed on 17 June 2022).
  10. Lavelle, E.C.; Ward, R.W. Mucosal Vaccines - Fortifying the Frontiers. Nat. Rev. Immunol. 2022, 22, 236–250. [Google Scholar] [CrossRef]
  11. INRAE A French Nasal Vaccine Project against COVID-19 Blocks All Transmission of the Virus—Another Step Taken. Available online: (accessed on 17 June 2022).
  12. Limbu, Y.B.; Gautam, R.K.; Pham, L. The Health Belief Model Applied to COVID-19 Vaccine Hesitancy: A Systematic Review. Vaccines 2022, 10, 973. [Google Scholar] [CrossRef]
  13. Juarez, R.; Phankitnirundorn, K.; Okihiro, M.; Maunakea, A.K. Opposing Role of Trust as a Modifier of COVID-19 Vaccine Uptake in an Indigenous Population. Vaccines 2022, 10, 968. [Google Scholar] [CrossRef]
  14. Savarese, G.; Carpinelli, L.; De Chiara, A.; Giordano, C.; Perillo, M.; Fornino, D.; De Caro, F.; Capunzo, M.; Moccia, G. Anti-SARS-CoV-2 Vaccination Campaign: Risk Perception, Emotional States, and Vaccine Hesitancy in a Sample of Adolescents’ Vaccinated Parents in Southern Italy. Vaccines 2022, 10, 958. [Google Scholar] [CrossRef] [PubMed]
  15. Bord, S.; Satran, C.; Schor, A. The Mediating Role of the Perceived COVID-19 Vaccine Benefits: Examining Israeli Parents’ Perceptions Regarding Their Adolescents’ Vaccination. Vaccines 2022, 10, 917. [Google Scholar] [CrossRef] [PubMed]
  16. Davis, T.C.; Beyl, R.; Bhuiyan, M.A.N.; Davis, A.B.; Vanchiere, J.A.; Wolf, M.S.; Arnold, C.L. COVID-19 Concerns, Vaccine Acceptance and Trusted Sources of Information among Patients Cared for in a Safety-Net Health System. Vaccines 2022, 10, 928. [Google Scholar] [CrossRef] [PubMed]
  17. Świerad, M.; Świerad, I.; Szydło, R.; Honisz, G.; Gąsior, M.; Kalarus, Z.; Dyrbuś, K. Assessment of the Level of Anxiety for COVID-19 Vaccinations. Vaccines 2022, 10, 915. [Google Scholar] [CrossRef] [PubMed]
  18. Del Riccio, M.; Bechini, A.; Buscemi, P.; Bonanni, P.; on behalf of the Working Group DHS; Boccalini, S. Reasons for the Intention to Refuse COVID-19 Vaccination and Their Association with Preferred Sources of Information in a Nationwide, Population-Based Sample in Italy, before COVID-19 Vaccines Roll Out. Vaccines 2022, 10, 913. [Google Scholar] [CrossRef] [PubMed]
  19. Shafqat, A.; Arabi, T.Z.; Sabbah, B.N.; Abdulkader, H.S.; Shafqat, S.; Razak, A.; Kashir, J.; Alkattan, K.; Yaqinuddin, A. Understanding COVID-19 Vaccines Today: Are T-Cells Key Players? Vaccines 2022, 10, 904. [Google Scholar] [CrossRef]
  20. Zhang, Z.; Mateus, J.; Coelho, C.H.; Dan, J.M.; Moderbacher, C.R.; Gálvez, R.I.; Cortes, F.H.; Grifoni, A.; Tarke, A.; Chang, J.; et al. Humoral and Cellular Immune Memory to Four COVID-19 Vaccines. Cell 2022, in press. [Google Scholar] [CrossRef]
  21. Cortés-Sarabia, K.; Gutiérrez-Torres, M.; Mendoza-Renteria, E.M.; Leyva-Vázquez, M.A.; Vences-Velázquez, A.; Hernández-Sotelo, D.; Beltrán-Anaya, F.O.; Del Moral-Hernández, O.; Illades-Aguiar, B. Variation in the Humoral Immune Response Induced by the Administration of the BNT162b2 Pfizer/BioNTech Vaccine: A Systematic Review. Vaccines 2022, 10, 909. [Google Scholar] [CrossRef]
  22. Padhiar, N.H.; Liu, J.-B.; Wang, X.; Wang, X.-L.; Bodnar, B.H.; Khan, S.; Wang, P.; Khan, A.I.; Luo, J.-J.; Hu, W.-H.; et al. Comparison of BNT162b2-, MRNA-1273- and Ad26.COV2.S-Elicited IgG and Neutralizing Titers against SARS-CoV-2 and Its Variants. Vaccines 2022, 10, 858. [Google Scholar] [CrossRef]
  23. Couzin-Frankel, J. What Causes Long Covid? Here Are the Three Leading Theories. Available online: (accessed on 19 June 2022).
  24. Hale, V.L.; Dennis, P.M.; McBride, D.S.; Nolting, J.M.; Madden, C.; Huey, D.; Ehrlich, M.; Grieser, J.; Winston, J.; Lombardi, D.; et al. SARS-CoV-2 Infection in Free-Ranging White-Tailed Deer. Nature 2022, 602, 481–486. [Google Scholar] [CrossRef]
  25. Martins, M.; Boggiatto, P.M.; Buckley, A.; Cassmann, E.D.; Falkenberg, S.; Caserta, L.C.; Fernandes, M.H.V.; Kanipe, C.; Lager, K.; Palmer, M.V.; et al. From Deer-to-Deer: SARS-CoV-2 Is Efficiently Transmitted and Presents Broad Tissue Tropism and Replication Sites in White-Tailed Deer. PLoS Pathog. 2022, 18, e1010197. [Google Scholar] [CrossRef] [PubMed]
  26. Oude Munnink, B.B.; Sikkema, R.S.; Nieuwenhuijse, D.F.; Molenaar, R.J.; Munger, E.; Molenkamp, R.; van der Spek, A.; Tolsma, P.; Rietveld, A.; Brouwer, M.; et al. Transmission of SARS-CoV-2 on Mink Farms between Humans and Mink and Back to Humans. Science 2021, 371, 172–177. [Google Scholar] [CrossRef] [PubMed]
  27. Jones, K.E.; Patel, N.G.; Levy, M.A.; Storeygard, A.; Balk, D.; Gittleman, J.L.; Daszak, P. Global Trends in Emerging Infectious Diseases. Nature 2008, 451, 990–993. [Google Scholar] [CrossRef] [PubMed]
  28. Meurens, F.; Dunoyer, C.; Fourichon, C.; Gerdts, V.; Haddad, N.; Kortekaas, J.; Lewandowska, M.; Monchatre-Leroy, E.; Summerfield, A.; Wichgers Schreur, P.J.; et al. Animal Board Invited Review: Risks of Zoonotic Disease Emergence at the Interface of Wildlife and Livestock Systems. Animal 2021, 15, 100241. [Google Scholar] [CrossRef] [PubMed]
  29. Mubareka, S.; Amuasi, J.; Carabin, H.; Jack, J.C.; Jardine, C.; Keefe, G.; Kutz, S.; McGregor, D.; Nicholson, L.; Parmley, E.J.; et al. Strengthening a One Health Approach to Emerging Zoonoses | The Royal Society of Canada. Available online: (accessed on 18 June 2022).
  30. Creech, C.B.; Anderson, E.; Berthaud, V.; Yildirim, I.; Atz, A.M.; Melendez Baez, I.; Finkelstein, D.; Pickrell, P.; Kirstein, J.; Yut, C.; et al. Evaluation of MRNA-1273 Covid-19 Vaccine in Children 6 to 11 Years of Age. N. Engl. J. Med. 2022, 386, 2011–2023. [Google Scholar] [CrossRef] [PubMed]
  31. Prasithsirikul, W.; Nopsopon, T.; Phutrakool, P.; Suwanwattana, P.; Kantagowit, P.; Pongpirul, W.; Jongkaewwattana, A.; Pongpirul, K. ChAdOx1 NCoV-19 Immunogenicity and Immunological Response Following COVID-19 Infection in Patients Receiving Maintenance Hemodialysis. Vaccines 2022, 10, 959. [Google Scholar] [CrossRef]
  32. Hammer, H.; Hoepner, R.; Friedli, C.; Leib, S.L.; Suter-Riniker, F.; Diem, L.; Kamber, N.; Chan, A.; Salmen, A.; Kamm, C.P. Comparison of MRNA Vaccinations with BNT162b2 or MRNA-1273 in Anti-CD20-Treated Multiple Sclerosis Patients. Vaccines 2022, 10, 922. [Google Scholar] [CrossRef]
  33. Cassaniti, I.; Gregorini, M.; Bergami, F.; Arena, F.; Sammartino, J.C.; Percivalle, E.; Soleymaninejadian, E.; Abelli, M.; Ticozzelli, E.; Nocco, A.; et al. Effect of a Third Dose of SARS-CoV-2 MRNA BNT162b2 Vaccine on Humoral and Cellular Responses and Serum Anti-HLA Antibodies in Kidney Transplant Recipients. Vaccines 2022, 10, 921. [Google Scholar] [CrossRef]
  34. Furer, V.; Eviatar, T.; Zisman, D.; Peleg, H.; Braun-Moscovici, Y.; Balbir-Gurman, A.; Paran, D.; Levartovsky, D.; Zisapel, M.; Elalouf, O.; et al. Predictors of Immunogenic Response to the BNT162b2 MRNA COVID-19 Vaccination in Patients with Autoimmune Inflammatory Rheumatic Diseases Treated with Rituximab. Vaccines 2022, 10, 901. [Google Scholar] [CrossRef]
  35. Chantasrisawad, N.; Puthanakit, T.; Tangsathapornpong, A.; Techasaensiri, C.; Phongsamart, W.; Suwanpakdee, D.; Jaruampornpan, P.; Sophonphan, J.; Suntarattiwong, P.; Chotpitayasunondh, T. Immunogenicity and Reactogenicity of MRNA BNT162b2 COVID-19 Vaccine among Thai Adolescents with Chronic Diseases. Vaccines 2022, 10, 871. [Google Scholar] [CrossRef]
  36. Choi, J.; Lieff, S.A.; Meltzer, G.Y.; Grivel, M.M.; Chang, V.W.; Yang, L.H.; Des Jarlais, D.C. Anti-Vaccine Attitudes among Adults in the U.S. during the COVID-19 Pandemic after Vaccine Rollout. Vaccines 2022, 10, 933. [Google Scholar] [CrossRef] [PubMed]
  37. Herman-Edelstein, M.; Ben-Dor, N.; Agur, T.; Guetta, T.; Raiter, A.; Meisel, E.; Alkeesh, W.; Ori, Y.; Rozen-Zvi, B.; Zingerman, B. BNT162b2 Booster Vaccination Induced Immunity against SARS-CoV-2 Variants among Hemodialysis Patients. Vaccines 2022, 10, 967. [Google Scholar] [CrossRef] [PubMed]
  38. Funakoshi, Y.; Yakushijin, K.; Ohji, G.; Hojo, W.; Sakai, H.; Watanabe, M.; Kitao, A.; Miyata, Y.; Saito, Y.; Kawamoto, S.; et al. Promising Efficacy of a Third Dose of MRNA SARS-CoV-2 Vaccination in Patients Treated with Anti-CD20 Antibody Who Failed 2-Dose Vaccination. Vaccines 2022, 10, 965. [Google Scholar] [CrossRef] [PubMed]
  39. Mingot-Castellano, M.E.; Butta, N.; Canaro, M.; del Castillo Solano, G.; del Carmen, M.; Sánchez-González, B.; Jiménez-Bárcenas, R.; Pascual-Izquierdo, C.; Caballero-Navarro, G.; Entrena Ureña, L.; et al. COVID-19 Vaccines and Autoimmune Hematologic Disorders. Vaccines 2022, 10, 961. [Google Scholar] [CrossRef]
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Meurens, F.; Renois, F.; Bouin, A.; Zhu, J. SARS-CoV-2 Vaccination: What Can We Expect Now? Vaccines 2022, 10, 1093.

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Meurens F, Renois F, Bouin A, Zhu J. SARS-CoV-2 Vaccination: What Can We Expect Now? Vaccines. 2022; 10(7):1093.

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Meurens, François, Fanny Renois, Alexis Bouin, and Jianzhong Zhu. 2022. "SARS-CoV-2 Vaccination: What Can We Expect Now?" Vaccines 10, no. 7: 1093.

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