Monoclonal antibodies protect aged rhesus macaques from SARS-CoV-2-induced immune activation and neuroinflammation

Anti-viral monoclonal antibody (mAb) treatments may provide immediate but short-term immunity from coronavirus disease 2019 (COVID-19) in high-risk populations, such as people with diabetes and the elderly; however, data on their efficacy in these populations are limited. We demonstrate that prophylactic mAb treatment blocks viral replication in both the upper and lower respiratory tracts in aged, type 2 diabetic rhesus macaques. mAb infusion dramatically curtails severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated stimulation of interferon-induced chemokines and T cell activation, significantly reducing development of interstitial pneumonia. Furthermore, mAb infusion significantly dampens the greater than 3-fold increase in SARS-CoV-2-induced effector CD4 T cell influx into the cerebrospinal fluid. Our data show that neutralizing mAbs administered preventatively to high-risk populations may mitigate the adverse inflammatory consequences of SARS-CoV-2 exposure. [Display omitted] •Neutralizing monoclonal antibodies (mAbs) block SARS-CoV-2 replication•Neutralizing mAbs prevent SARS-CoV-2-induced interferon-induced chemokines•Neutralizing mAbs limit effector CD4 T cell influx into cerebrospinal fluid Verma et al. observe that prophylactic mAbs limit SARS-CoV-2 replication and immune activation. In aged diabetic rhesus macaques, these protective mechanisms took place in the areas of the body most highly targeted by the virus and the respiratory, nervous, and circulatory systems.