Chadi and Caroline join TWiV to describe the potential epidemiological and evolutionary impacts of vaccine nationalism, and their modeling which emphasizes the importance of rapid equitable vaccine distribution for global control of the pandemic.
The TWiVotopes review current evidence which does not show the need for widespread COVID-19 booster vaccination, and results of experiments to examine the replication and immune evasion of the SARS-CoV-2 delta variant.
Virus hunter Mya Breitbart joins TWiV to describe her laboratory’s work on viruses in spiders, insects, millipedes, freshwater springs, seawater, plants, human feces and much more.
Shane Crotty returns to TWiV to review the immunology of COVID-19, including differences between infection and vaccination, increased breadth of antibodies after infection followed by vaccination, the roles of T cells, and whether booster vaccinations are needed.
The meteorologicomaniacs discuss the COVID-19 pandemic global death toll, effectiveness of vaccines against the delta variant, and how analysis of ancient viral DNA reveals that two pathogenic human viruses were brought into Mexico during the transatlantic slave trade.
Jeffrey Shaman returns to TWiV to explain how epidemiologists measure SARS-CoV-2 movement among humans, including calculation of the reproductive index, secondary transmission, and what factors affect transmission.
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.
Kiran joins TWiV to discuss the findings of a team at Columbia University Medical Center on COVID-19 neuropathology, and the conclusion that SARS-CoV-2 does not reproduce in the central nervous system.
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.