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.

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.

In COVID-19 clinical update #77, Daniel Griffin discusses children becoming increasingly infected, virological characteristics of infections in vaccinated health care workers, transmission dynamics among close contacts, licensing of Pfizer mRNA vaccine, cost of hospitalization of unvaccinated patients, 29 times higher hospitalization rates in unvaccinated patients, boost in neutralizing antibody potency and breadth by third vaccine dose, and use of J&J vaccine as second dose.

Paul and Theodora return to TWiV to explain their research on determining the number of neutralizing epitopes on the SARS-CoV-2 spike that are recognized by antibodies, and engineering of a polymutant spike with twenty amino acid changes that demonstrates the high genetic barrier to escape from convalescent serum.

In COVID-19 clinical update #76, Daniel Griffin covers association of age and pediatric household transmission, rapid antigen testing in remote communities, shedding of infectious virus in vaccinated individuals, FDA amendment of mRNA vaccine EUA to allow a third dose, new vaccine mandate for NY state, full vaccination suppresses selection of variants, effectiveness of mRNA vaccines in nursing homes, sustained effectiveness of mRNA vaccines against hospitalization, and no benefit from early convalescent serum in high-risk outpatients.

In COVID-19 clinical update #75, Daniel Griffin reviews vaccine effectiveness against transmission, modeling effectiveness of daily antigen tests, updated CDC guidance for fully vaccinated, risk of infection with time after mRNA vaccination, reduced risk of infection after vaccination, therapeutic anticoagulants in critically ill patients, and 6 month outcomes in hospitalized patients.