By Jennifer Juno Senior research fellow, The Peter Doherty Institute for Infection and Immunity Adam Wheatley Senior Research Fellow, Department of Microbiology and Immunology, The University of Mel Melbourne, Nov 29 The Conversation The emergence of a new SARS-CoV-2 variant of concern, Omicron, has reignited global discussions of vaccine distribution, virus mutation, and immunity against new virus strains.Some experts have suggested the emergence of a new strain could be a result of low levels of vaccine coverage in developing nations.So how do new virus variants emerge