TWiV reviews findings that increased fitness of the Omicron variant is due to immune evasion, not an increase in intrinsic transmissibility, and determination of infectious viral load in patients infected with wild type, Delta and Omicron viruses reveals lack of correlation with RNA loads determined by RT-PCR, similar levels of shedding among Delta and Omicron, and greatly reduced shedding in vaccinated people.

In COVID-19 clinical update #97, Daniel Griffin covers immunity after infection recognized by CDC, outcomes before and after Omicron, infectious viral load in Delta vs Omicron, PCR vs rapid antigen tests, booster interval shortened to 5 months, risk factors for severe outcomes in vaccinated, cross-reactive memory T cells, vaccine effectiveness vs MIS-C, and Rivaroxiban for thromboprophylaxis.

In COVID-19 clinical update #96, Daniel Griffin reviews Omicron in South Africa, rapid antigen tests, viral coinfections, isolation and quarantine, saliva preferred for Omicron, risk factors for severe disease in vaccinated, Paxlovid dosing, and long COVID.

In COVID-19 clinical update #95, Daniel Griffin discusses new CDC guidelines for isolation and quarantine, EUA for Molnupiravir, children and COVID, vaccine safety in 5-11 year olds, Omicron outbreaks in Nebraska and Denmark, Baylor’s COVID vaccine, and COVID-OUT for ivermectin.

In COVID-19 clinical update #94, Daniel Griffin reviews the FDA EUA for Paxlovid, test to stay in school, immunity after infection, variants and therapeutics, quarantine and isolation guidelines, Molnupiravir in non-hospitalized patients, and convalescent serum in outpatients.

In COVID-19 clinical update #93, Dr. Griffin summarizes Omicron fitness, S-gene target failure, monoclonal efficacy against Omicron, vaccination, monoclonals, and disease in children, persistence of memory B cells in the elderly, infection and vaccine induced immunity, protection against severe illness and death by a third mRNA vaccine dose, high flow oxygen versus intubation, and therapeutic anticoagulation.

In COVID-19 clinical update #92, Dr. Griffin reviews emerging data on the Omicron variant, much information about monoclonal antibody treatment, including expansion of EUA for Lilly’s cocktail, FDA EUA for pre-exposure prophylaxis, outcomes after treatment, and investigation of subcutaneous or intramuscular administration; effect of adding immunomodulatory agents to usual care on thromboembolic events, and long COVID following infection in previously vaccinated individuals.