Prone-to-Infectivity of Omicron BA.2 Subvariant from Indonesia on ACE-2 Expressing Cell Lines

Abstract

SARS-CoV-2 virus undergoes mutation, leading to the virus's evolution and modifications in the characteristics of the virus. Omicron, including BA.2 subvariant, is currently the predominant variant in SARS-CoV-2 infection. There are no reports regarding its properties or the utilization of BA.2 Indonesian isolate for therapy and vaccine development. Therefore, this study evaluated appropriate host cells for Omicron BA.2 Indonesian isolate via susceptibility tests. The Omicron BA.2 from Indonesia was exposed to three mammalian-ACE2-expressing cell lines. Sharing amino acids between BA.2 from Indonesia and previous VOC Omicron subvariants was performed using a simple in silico comparison method. The results showed that the virus could not infect HepG2 and Huh-7D12 due to no foci forming on those cell lines. Moreover, we also found that BA.2 Indonesian isolate has a unique amino acid alteration on spike protein. According to the findings, the Omicron BA.2 from Indonesia could propagate on Vero E6 cell lines, and the mutations could play a role in the virus's changing infection mechanism. A deeper in vitro and in silico experiment could enhance the findings by comparing all BA.2 sequences from Indonesia and analyzing the infection mechanism by each single mutation using pseudovirus.