Compromised CD8+ T cell immunity in the aged brain increases severity of neurotropic coronavirus infection and postinfectious cognitive impairment.

Advanced age increases the risk of severe disease from SARS-CoV-2 infection, as well as incidence of long COVID and SARS-CoV-2 reinfection. We hypothesized that perturbations in the aged antiviral CD8 T cell response predisposes elderly individuals to severe coronavirus infection, re-infection, and postinfectious cognitive sequelae. Using MHV-A59 as a murine model of respiratory coronavirus, we found that aging increased CNS infection and lethality to MHV infection.

Antigen non-specific CD8 T cells accelerate cognitive decline in aged mice following respiratory coronavirus infection.

Primarily a respiratory infection, numerous patients infected with SARS-CoV-2 present with neurologic symptoms, some continuing long after viral clearance as a persistent symptomatic phase termed "long COVID". Advanced age increases the risk of severe disease, as well as incidence of long COVID. We hypothesized that perturbations in the aged immune response predispose elderly individuals to severe coronavirus infection and post-infectious sequelae.