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.

In COVID-19 clinical update #79, Daniel Griffin discusses clinical management guidelines, ER visits and hospitalization among children, infection and vaccine induced seroprevalence in the US, antibodies in Kenyan blood donors, infections after vaccination, anticoagulation for thromboprophylaxis, baracitinib efficacy, long-term symptoms in adults, and sustained symptoms after severe disease.

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.

In COVID-19 clinical update #78, Daniel Griffin covers ivermectin, convalescent plasma, disease in pregnant women, children and COVID, delta outbreak in an elementary school, validation of at-home antigen test, shedding in infected vaccinated people, mRNA vaccine antibody responses compared, AZD7442, fluvoxamine, one year outcomes in hospitalized patients, and post-vaccination disease.