New variants of SARS-CoV-2, vaccine immune response and the Brazilian reality

Marileia Andrade,Luiza Gomes,Hellen Rosa,Vitória Mendes

doi:10.37349/ei.2021.00029

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly pathogenic β-coronavirus, is the etiologic agent of coronavirus disease 2019 (COVID-19), which gave rise to a difficult to control pandemic, especially in Brazil. Approximately 4,000 mutations have been identified in SARS-CoV-2, with the majority being redundant without having any biological effect on the virus. The aim of the present study was to objectively understand how new SARS-CoV-2 variants can affect vaccine response, in addition to highlighting the current situation in Brazil in the face of the pandemic and considering epidemiological and immunological aspects of COVID-19. The main protective correlate investigated in most vaccines is the neutralizing antibody titer induced by immunizing agents, observed in the pre-clinical phase in animals, whose action is to block the binding of the spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor, preventing infection. Up to the second half of 2021, the variants that are of greatest concern worldwide and require molecular surveillance are Alpha variant (or B.1.1.7 lineage), Beta (or B.1.351 lineage), Gamma (or P1 lineage) and Delta (or B.1.617.2 lineage). Brazil finds itself in a highly unfavorable scenario, with the circulation of variants of concern, mainly Gamma and Delta, with high fatality rates for COVID-19 and low vaccination rate. Given the still latent situation of the COVID-19 pandemic in Brazil, the lack of global planning for action strategies for non-pharmacological prevention measures, there is an imminent risk of the emergence of new variants due to the finding of susceptible hosts and the high proliferative rate of SARS-CoV-2. It is urgent to increase the genotyping of positive samples isolated from infected individuals, the speed of vaccination of the entire population and the unification of non pharmacological preventive measures throughout the country.

Highlights

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly pathogenic β-coronavirus, is the etiologic agent of coronavirus disease 2019 (COVID-19), which gave rise to a difficult to control pandemic, especially in Brazil [1]
4,000 mutations have been identified in SARS-CoV-2, with the majority being redundant without having any biological effect on the virus
The main protective correlate investigated in most vaccines is the neutralizing antibody titer induced by immunizing agents, observed in the pre-clinical phase in animals, whose action is to block the binding of the spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor, preventing infection

Summary

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly pathogenic β-coronavirus, is the etiologic agent of coronavirus disease 2019 (COVID-19), which gave rise to a difficult to control pandemic, especially in Brazil [1]. As a process inherent to all viruses, SARS-CoV-2 undergoes mutations in its RNA (Ribonucleic acid) genome at each replication, resulting in different biological effects, which are subjected to natural selection processes. These mutations vary from having an irrelevant or null effect (no consequences), being harmful to the virus itself (negative effect) or having positive effects. Their biological function may not be fully understood, but they may be of great epidemiological importance, given that evidence shows that some mutations are able to favor viral maintenance and increase infectivity [5]. 4,000 mutations have been identified in SARS-CoV-2, with the majority being redundant without having any biological effect on the virus [6]

Objectives

Findings

Conclusion