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Review
. 2023 Mar 5;59(3):507.
doi: 10.3390/medicina59030507.

Variants of SARS-CoV-2: Influences on the Vaccines' Effectiveness and Possible Strategies to Overcome Their Consequences

Ali A Rabaan  1   2   3 , Shamsah H Al-Ahmed  4 , Hawra Albayat  5 , Sara Alwarthan  6 , Mashael Alhajri  6 , Mustafa A Najim  7 , Bashayer M AlShehail  8 , Wasl Al-Adsani  9   10 , Ali Alghadeer  11 , Wesam A Abduljabbar  12 , Nouf Alotaibi  13 , Jameela Alsalman  14 , Ali H Gorab  15 , Reem S Almaghrabi  16 , Ali A Zaidan  17 , Sahar Aldossary  18 , Mohammed Alissa  19 , Lamees M Alburaiky  20 , Fatimah Mustafa Alsalim  21 , Nanamika Thakur  22 , Geetika Verma  23 , Manish Dhawan  24   25
Affiliations
Review

Variants of SARS-CoV-2: Influences on the Vaccines' Effectiveness and Possible Strategies to Overcome Their Consequences

Ali A Rabaan et al. Medicina (Kaunas). .

Abstract

The immune response elicited by the current COVID-19 vaccinations declines with time, especially among the immunocompromised population. Furthermore, the emergence of novel SARS-CoV-2 variants, particularly the Omicron variant, has raised serious concerns about the efficacy of currently available vaccines in protecting the most vulnerable people. Several studies have reported that vaccinated people get breakthrough infections amid COVID-19 cases. So far, five variants of concern (VOCs) have been reported, resulting in successive waves of infection. These variants have shown a variable amount of resistance towards the neutralising antibodies (nAbs) elicited either through natural infection or the vaccination. The spike (S) protein, membrane (M) protein, and envelope (E) protein on the viral surface envelope and the N-nucleocapsid protein in the core of the ribonucleoprotein are the major structural vaccine target proteins against COVID-19. Among these targets, S Protein has been extensively exploited to generate effective vaccines against COVID-19. Hence, amid the emergence of novel variants of SARS-CoV-2, we have discussed their impact on currently available vaccines. We have also discussed the potential roles of S Protein in the development of novel vaccination approaches to contain the negative consequences of the variants' emergence and acquisition of mutations in the S Protein of SARS-CoV-2. Moreover, the implications of SARS-CoV-2's structural proteins were also discussed in terms of their variable potential to elicit an effective amount of immune response.

Keywords: COVID-19; Omicron; SARS-CoV-2; breakthrough infections; neutralizing antibodies (NAbs); vaccines; variants.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The schematic representation of the SARS-CoV-2 entry into the host cell. (A) Representation of the S Protein and its various regions such as receptor binding domain (RBD); (B) Binding of the S Protein with the ACE2 receptor of the host cell. After binding of the S Protein with the ACE2 receptor, there is cleavage of the S Protein into S1 and S2 sites. Activated S2 domain helps in the fusion of the viral particle with the cell membrane. [The figure was created with the templates available in BioRender.com, accessed on 25 January 2023].
Figure 2
Figure 2
The principal targets of candidates for the COVID-19 vaccination; Source: [137].
Figure 3
Figure 3
Trend of major mutations in the spike protein from December 2020 to March 2021. [Source: https://www.news-medical.net/news/20210427/Triple-mutation-in-SARS-CoV-2-seen-in-second-wave-of-COVID-19-in-India.aspx, accessed on 15 January 2023].
See this image and copyright information in PMC

References

    1. COVAX. [(accessed on 8 January 2023)]. Available online: https://www.who.int/initiatives/act-accelerator/covax.
    1. Fontanet A., Autran B., Lina B., Kieny M.P., Karim S.S.A., Sridhar D. SARS-CoV-2 Variants and Ending the COVID-19 Pandemic. Lancet. 2021;397:952. doi: 10.1016/S0140-6736(21)00370-6. - DOI - PMC - PubMed
    1. Wang Z., Schmidt F., Weisblum Y., Muecksch F., Barnes C.O., Finkin S., Schaefer-Babajew D., Cipolla M., Gaebler C., Lieberman J.A., et al. MRNA Vaccine-Elicited Antibodies to SARS-CoV-2 and Circulating Variants. Nature. 2021;592:616–622. doi: 10.1038/s41586-021-03324-6. - DOI - PMC - PubMed
    1. Moore J.P., Offit P.A. SARS-CoV-2 Vaccines and the Growing Threat of Viral Variants. JAMA. 2021;325:821–822. doi: 10.1001/jama.2021.1114. - DOI - PubMed
    1. Madhi S.A., Baillie V., Cutland C.L., Voysey M., Koen A.L., Fairlie L., Padayachee S.D., Dheda K., Barnabas S.L., Bhorat Q.E., et al. Efficacy of the ChAdOx1 NCoV-19 COVID-19 Vaccine against the B.1.351 Variant. N. Engl. J. Med. 2021;384:1885–1898. doi: 10.1056/NEJMoa2102214. - DOI - PMC - PubMed

Supplementary concepts