The TWiVmeisters discuss how copy-back defective viral genomes might modulate the clinical outcome of respiratory syncytial virus infection, and detection of antibodies to henipa- and filo-like viruses in Trinidad bats.

A TWiV trio explains a method for sequencing single genomes of SARS-CoV-2 and its use to explore in-host evolution drive by antibody responses, and incidence of cerebral venous thrombosis in COVID-19 patients and vaccine recipients.

In COVID-19 clinical update #59, Daniel Griffin discusses a front-line health care worker survey, pre-exposure seropositivity and subsequent infection in healthy young adults, fitted filtration efficiency of double masking, BinaxNow rapid in-home antigen test, postvaccination infections in a nursing facility, safety of mRNA vaccine in pregnant women, case control study of Bamlanivimab, no evidence for brain infection in patients with neurolgical symptoms, and mortality among US patients hospitalized with COVID-19.

The TWiVsters explain how the shape of pleomorphic virus particles – spherical or filamentous – determines the probability of virus attachment and fusion, and resistance to selective pressure such as antibodies that block cell entry.

TWiV reviews a drug screen for inhibitors of syncytium formation, the fusing of cells caused by SARS-CoV-2, which reveals that the process is regulated by a calcium-activated ion channel and scramblase that is inhibited by the anti-parasite drug Niclosamide.