Role of COVID-19 Vaccines in SARS-CoV-2 Variants

Abstract

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a threat to the health of the global population. As the result of a global effort in the determination of origin, structure, and pathogenesis of SARS-CoV-2 and its variants, particularly such the variant of concern as Delta Variant and Omicron Variant, the understanding of SARS-CoV-2 are deepening and the development of vaccines against SARS-CoV-2 are ongoing. Currently, AstraZeneca-Vaxzevria/SII-Covishield vaccine, Janssen-Ad26.COV2.S vaccine, Moderna-mRNA-1273 vaccine, Pfizer BioNTech-Comirnaty vaccine and Sinovac-CoronaVac vaccine have been listed as WHO Emergency Use Listing (EUL) Qualified Vaccines by WHO. Because of the antigen escape caused by the mutation in variants, the effectiveness of vaccines, which are currently the main means of prevention and treatment, has been affected by varying degrees. Herein, we review the current status of mutations of SARS-CoV-2 variants, the different approaches used in the development of COVID-19 vaccines, and COVID-19 vaccine effectiveness against SARS-CoV-2 variants.

Keywords: COVID-19; COVID-19 vaccines; Delta variant; Omicron variant; SARS-CoV-2.

Figure 1

The structure and genome organization of SARS-CoV-2. (A) Four structural proteins in SARS-CoV-2 are the spike (S), envelope (E), nucleocapsid (N) and membrane (M). S, E and M are embedded in the lipid bilayer envelope while RNA are coated by N. (B) The genome of SARS-CoV-2 consists of 13-15 open reading frames and encodes protein which plays important role in binding and translation between the virus and the host cell.

Figure 2

Timeline of Pfizer BioNTech-Comirnaty vaccine, AstraZeneca-Vaxzevria vaccine, Moderna-mRNA-1273 vaccine, Janssen-Ad26.COV 2.S vaccine and Sinovac-CoronaVac vaccine listed in WHO EUL recommendation.