TWiV discusses efficacy of this season’s flu vaccine, efficacy of Pfizer RSV vaccine, nOPV2 in the US, dengue in Peru, measles in Michigan and Indiana, how coordinated inflammatory responses dictate control of Marburg virus by reservoir bats, and tRNA acquisition in phages driven by degradation of host translational machinery.

TWiV explains why this season’s influenza vaccine is not protecting against mild to moderate disease caused by H3N2 virus, and that antibody-dependent entry of SARS-CoV-2 into monocytes is a major contributor to severe COVID-19.

On this episode of TWiV, Novavax COVID-19 vaccine demonstrates 90% overall efficacy, preventing an antigenically disruptive change during growth of influenza virus vaccine in chicken eggs, and MIS-C is driven by loss of the gut mucosal barrier.

Daniel Griffin provides a clinical report on COVID-19, then we discuss decline of virus-specific bone marrow B cells within a year after influenza vaccination, the push to release SARS-CoV-2 vaccines before completion of phase 3 trials, and absence of evidence for infectious virus in aerosols.

TWiV provides updates on the new coronavirus causing respiratory disease in China, the current influenza season, and the epidemic of African swine fever, including determination of the three-dimensional structure of the virus particle.

For the first TWiV of 2020 we reveal that microbiome depletion with antibiotics alters the immune response to influenza vaccine, and how successive blood meals facilitate virus dissemination in mosquitoes and transmission potential.

The League of Extraordinary Virologists celebrate the eradication of wild poliovirus type 3, and consider the effectiveness of an influenza vaccine produced in insect cells, and how small RNAs are protecting the Koala germline from retroviral invasion.

The TWiVonauts review how the weather affects West Nile virus disease in the US, benefit of B cell depletion for ME/CFS patients, and an autoimmune reaction induced by influenza virus vaccine that leads to narcolepsy.