Introduction of ORF3a-Q57H SARS-CoV-2 Variant Causing Fourth Epidemic Wave of COVID-19, Hong Kong, China

Emerg Infect Dis. 2021 May;27(5):1492-1495. doi: 10.3201/eid2705.210015.


We describe an introduction of clade GH severe acute respiratory syndrome coronavirus 2 causing a fourth wave of coronavirus disease in Hong Kong. The virus has an ORF3a-Q57H mutation, causing truncation of ORF3b. This virus evades induction of cytokine, chemokine, and interferon-stimulated gene expression in primary human respiratory cells.

Keywords: COVID-19; China; Hong Kong; SARS; SARS-CoV-2; coronavirus; coronavirus disease; respiratory infections; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19*
  • China
  • Epidemics*
  • Hong Kong / epidemiology
  • Humans
  • SARS-CoV-2