For the last episode of 2023, TWiV describes how ancient chicken remains reveal the increase of fitness and virulence of Marek’s disease virus, and the diversity and dissemination of Leishmania virus in the pathogenic protozoan Leishmania braziliensis.
TWiV discusses whether or not Omicron should be designated a new serotype of SARS-CoV-2, and the finding that amino acid changes that adapt SARS-CoV-2 to mink or ferret do not increase fitness in the human airway.
TWiV reveals all that we know so far about the variant of concern B.1.1.529, also called Omicron, and describes a study on the ability of the alpha, beta, and delta variants to reproduce in cells in culture and induce membrane fusion.
TWiV reviews a leaked CDC document on virulence and spread of the delta variant, and how anti-alphavirus antibodies that do not neutralize infection can nevertheless protect mice from disease.
Ron Fouchier explains why increased transmission of SARS-CoV-2-variants has not been demonstrated, and their ability to displace ancestral variants is due to greater fitness, much like influenza virus antigenic variation leads to better fitness and replacement of previously circulating variants.
The Hosts of TWiV
Vincent Racaniello, Ph.D.
Dickson D.
Despommier, Ph.D.
Alan Dove, Ph.D.
Daniel Griffin, M.D.,
Ph.D., CTropMed CTH
Jolene Ramsey, Ph.D.