Title: More mysteries of COVID-19 outbreak

Speaker: Dr. Ting-Yu Yeh (Co-Founder and Chief Scientific Officer, Auxergen, Inc)

If you would like to attend this seminar virtually, please contact imetdirectorsoffice@umces.edu for the WebEx call-in information

Abstract: The 2019 novel coronavirus disease (COVID-19) outbreak has become a public health emergency globally since January 2020. In addition to pneumonia-like symptoms, COVID-19 also develops a significant systemic inflammatory response, and it also attacks neurological and cardiovascular systems. As pandemic deepens, SARS-CoV-2 has quickly evolved into several clades at different geographic areas. Whether SARS-CoV-2 variants contribute to etiology and epidemiology of COVID-19 remains unclear. Here I report the evolution and phylogenetic analysis of SARS-CoV-2 mutations in Australia and Diamond Princess cruise. Analysis of Australian SARS-CoV-2 sequences reveals unusual deletions and mutations clustering in stem-loop II motif (s2m) in 3’ untranslated region, which is extremely conserved in all beta-coronavirus and astrovirus during evolution. Computational analysis of Australian isolates suggests that s2m may act as the hotspot for viral RNA recombination. The quarantine of Diamond Princess cruise presents an ideal static population to measure the viral phylodynamics from the COVID-19 outbreak, providing the first insight into the de novo evolution of SARS-CoV-2 in a closed population. Accelerated mutation and increased positive selection of SARA-CoV-2 are statistically significant during the quarantine period of 3 weeks. Linkage disequilibrium analysis confirmed that RNA recombination with G11083T (ORF1ab L3606F/NSP6 L37F) mutation also contributes to the increase of mutations among the viral progeny in the cruise. Therefore, health authorities need to revise quarantine protocols in close-quarter environments.