A Systematic review of SARS-CoV-2 mutations in relation to its Pathogenicity / Paula Kristen I. Acal, Alron Troy G. Alde, Yyona Pauline R. Alvarez, Althea C. Bajon, Sheena Mae R. Bobier, Josephine Ann G. De Jesus, Kessathea P. Dela Cruz, Jo Arrym B. Dellosa, Megan Margery A. Dulatre, Kyra Victorien V. Dimalanta, Kyla Alexa N. Ecalla, Charlotte Angela B. Fayloga, Marc Lester T. Fermin, Therese Bianca C. Flores, Krizza Mae A Francisco, Keena Marie C. Gaditano, Maria Ana Therese D.R. Garong, Maureen Diane C. Geli, Kristine Ann B. Geronaga, Genree Ann B. Gille and Paula Marie Humilde ; Polly Chua-Chan.

Includes bibliographical references.

Abstract: The rapid spread of COVID-19 by SARS-CoV-2 has caused an alarming and dramatic increase in cases globally. Findings from different studies suggest that one cause of this increased infectivity lies in the evolution of the virus and the emergence of different strains. Some strains might coexist with one another but have different mutation patterns. Currently, there are 8 novel mutations of SARS-Cov-2 that were observed from different countries around the world. Recently two more have been identified this early 2021. This paper provides a systematic review of the different mutations and an understanding of its pathogenic mechanisms in relation to pathogenicity and mortality. A systematic literature search was conducted in the study using different databases and grouping findings for discussion. The gathered data have proven that certain variants have developed specific mutations, which provided the identification of the changes in its structure, thus causing its several significant pathophysiologic effects on its host. One of which is the most common and dominant variant that is responsible for the massive increase in the past and current cases, as well as the leading cause of fatality as of to date is the variant D614G. With its mutations characterized by an amino acid substitution that replaces aspartic with glycine on codon 614, this resulted to an increased Spike protein in corporation into the virion, resulting to an increased viral stability and flexibility, thus conferring the variant a higher rate of infectivity as well as of enhanced pathogenicity. Another in the N501Y variant which was observed to have rapidly spread throughout the UK during early 2021. This variant has been correlated to have an ability for immune escape, whereby mutations on its three amino acids on the RBD region, Specifically on the N501Y single residue has produced its neutralization resistance. Therefore, the variant's acquired capability to avoid antibodies has not only decreased its sensitivity for the host's immune response, but it also has compromised the efficacy of the existing vaccines that we now have today. Several variants of SARS-CoV-2 were identified and categorized in our study and results show that mutations affect the pathogenic mechanisms of the virus which results in varying effects on transmission, pathogenicity and mortality.

Thesis - Department of Community & Family Medicine