TWiV reviews SARS-CoV-2 infection of wild white-tailed deer in the US, mRNA vaccine-mediated protection by spike-specific T cells before detection of neutralizing antibodies, and recovery from SARS-CoV-2 infection in T-cell depleted rhesus macaques.

In COVID-19 clinical update #74, Daniel Griffin covers infections in vaccinated individuals, expansion of Regeneron monoclonal antibody cocktail for prophylaxis, neutralization of variants by antibodies produced by infection or vaccination, longer hospital stays associated with remdesivir treatment, and post-acute sequelae of infection and impact on quality of life 1-6 months after illness.

TWiV reviews a leaked CDC document on virulence and spread of the delta variant, and how anti-alphavirus antibodies that do not neutralize infection can nevertheless protect mice from disease.

In COVID-19 clinical update #73, Daniel Griffin reviews updated mask guidance from CDC, infections in public school district employees, effectiveness of vaccines against delta variant, antibody response after third vaccine dose in kidney transplant recipients, protection afforded by mRNA vaccines fully vaccinated people with and without prior infections, correlates of protection in nonhuman primates, lack of effectiveness of doxycycline, neurological manifestations of COVID-19, and infection in vaccinated health care workers.

TWiVsters review off-season epidemics of respiratory syncytial virus in Australia after easing of COVID-19 restrictions, and impaired innate immune responses in upper respiratory tract cells from patients with severe COVID-19.

In COVID-19 clinical update #72, Daniel Griffin covers long term symptoms in children, outcomes for MIS-C, recent guidance from the American Academy of Pediatrics, a large well traced outbreak of delta variant, low dose mRNA vaccination generates durable T cell memory and antibodies, protective immunity in recovered patients, assessment of BinaxNOW, no effect of oral azithromycin, post-discharge symptoms in Nigeria, and therapeutics for low and middle income countries.

On this episode, broadening of immune responses to SARS-CoV-2 after mRNA vaccine booster to ChAdOx1 nCoV-19, five-fold underestimation of the number of cases in the US during the first six months of the pandemic, and a monoclonal antibody that broadly neutralizes many different sarbecoviruses.