In COVID-19 clinical update #63, Daniel Griffin reviews cases at child care facilities, estimates of mRNA vaccine effectiveness, risk of reinfection in university students, enhanced antibody generation with extended interval of mRNA vaccination, no benefit of convalescent plasma in hospitalized patients, and risk of clinical sequelae after acute infection.

TWiV reveals that 2% of SARS-CoV-2−positive individuals carry 90% of the virus circulating in a college campus, and a nanoparticle vaccine that induces cross-reactive immunity against multiple pandemic and pre-emergent coronaviruses.

TWiV returns to the 2012 brouhaha over transmission experiments with avian H5N1 influenza virus, re-examines the claim of SARS-CoV-2 RNA integration into human DNA, and reviews the engineering and testing of a genetically stable version of the attenuated type 2 Sabin poliovirus vaccine.

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.