SARS-CoV-2 Vaccines Based on the Spike Glycoprotein and Implications of New Viral Variants

Abstract

Coronavirus 19 Disease (COVID-19) originating in the province of Wuhan, China in 2019, is caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), whose infection in humans causes mild or severe clinical manifestations that mainly affect the respiratory system. So far, the COVID-19 has caused more than 2 million deaths worldwide. SARS-CoV-2 contains the Spike (S) glycoprotein on its surface, which is the main target for current vaccine development because antibodies directed against this protein can neutralize the infection. Companies and academic institutions have developed vaccines based on the S glycoprotein, as well as its antigenic domains and epitopes, which have been proven effective in generating neutralizing antibodies. However, the emergence of new SARS-CoV-2 variants could affect the effectiveness of vaccines. Here, we review the different types of vaccines designed and developed against SARS-CoV-2, placing emphasis on whether they are based on the complete S glycoprotein, its antigenic domains such as the receptor-binding domain (RBD) or short epitopes within the S glycoprotein. We also review and discuss the possible effectiveness of these vaccines against emerging SARS-CoV-2 variants.

Large-scale study of antibody titer decay following BNT162b2 mRNA vaccine or SARS-CoV-2 infection

“…However, in recent weeks, there has been a resurgence of SARS-CoV-2 cases in Israel. It is important to understand to what extent this resurgence is due to the high infectiousness of the delta variant(Chakraborty et al, 2021), lower protection of the vaccine against the delta or other variants as compared to the original strain(Faulkner et al, 2021; Martínez-Flores et al, 2021), or decreasing levels of anti-SARS-CoV-2 antibodies against all strains in vaccinated individuals(Israel et al, 2021).…”

SARS-CoV-2 Delta (B.1.617.2) Variant: A Unique T478K Mutation in Receptor Binding Motif (RBM) of Spike Gene

“…COVID-19 vaccines were distributed all over the world since January 2021, with some differences between countries. Mainly, there are 4 types of current COVID-19 vaccines; whole SARS-CoV-2 virus, mRNA, adenovirus, and subunit recombinant protein, which are almost based on the genetic information of spike ( S ) gene on the envelop of SARS-CoV-2 except SARS-CoV-2 viral vaccine ( 19 20 21 22 ). The S gene codes 1,273 amino acid residues with a signal peptide at N-terminus and a single a-helix transmembrane domain following a short cytosolic domain.…”

CoV-RBD121-NP Vaccine Candidate Protects against Symptomatic Disease following SARS-CoV-2 Challenge in K18-hACE2 Mice and Induces Protective Responses That Prevent COVID-19-Associated Immunopathology

“…Despite ongoing efforts, options for successful intervention after infection with SARS-CoV-2 remain of limited usefulness. In contrast, vaccination is a proven strategy to reduce both the severity and frequency of infection, and vaccines targeting the S protein of SARS-CoV-2 have proven effective in significantly reducing morbidity and mortality [9,10]. However, the continued emergence of variants and increasing severity of resulting economic crises following multiple waves of the pandemic has led to an unprecedented race to develop and deliver new and effective vaccine platforms that can be rapidly adapted to virus mutations and that produce vaccines that can be rapidly manufactured and distributed worldwide.…”