TWiV discusses the finding that the envelope (E) protein of SARS-CoV-2 is sensed by toll-like receptor 2 on cells, leading to the production of inflammatory cytokines that cause damage to cells and tissues in COVID-19.

TWiV revisits Brazil’s rejection of Sputnik vaccine, examines influenza transmission via the air from the nasal epithelium of ferrets, and a history of accidental releases of polioviruses and their relevance for eradication of poliomyelitis.

In COVID-19 clinical update #61, Daniel Griffin reviews a modeling of future hospitalizations and deaths by vaccination rates and non pharmaceutical intervention scenarios, performance evaluation of rapid antigen tests, children making up a growing share of new cases, antibody response to mRNA vaccine in solid organ transplant recipients, and outcomes in hospitalized patients treated with tocilizumab.

TWiV examines the claim by Brazil’s ANVISA that the Sputnik vaccine contains replication-competent adenovirus, and a role for the furin cleavage site in SARS-CoV-2 spike for efficient reproduction in the respiratory tract, evasion of antiviral IFITM proteins, and transmission in ferrets.

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.

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.