COVID-19 is currently a global pandemic, but human immune responses to the virus remain poorly understood. We analyzed 125 COVID-19 patients, and compared recovered to healthy individuals using high dimensional cytometry. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three “immunotypes” associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.

Highlights d Ly108 and CD69 define four Tex subsets linked in a hierarchical developmental pathway d Two TCF1+ subsets, effector-like and terminally exhausted subsets, are identified d Key transcriptional, epigenetic, and biological changes define subset transitions d TCF1, T-bet, and Tox coordinate Tex subset development and dynamics

Heterogeneity is a hallmark feature of the adaptive immune system in vertebrates. Following infection, naive T cells differentiate into various subsets of effector and memory T cells, which help to eliminate pathogens and maintain long-term immunity. The current model suggests there is a single lineage of naive T cells that give rise to different populations of effector and memory T cells depending on the type and amounts of stimulation they encounter during infection. Here, we have discovered that multiple sub-populations of cells exist in the naive CD8 T cell pool that are distinguished by their developmental origin, unique transcriptional profiles, distinct chromatin landscapes, and different kinetics and phenotypes after microbial challenge. These data demonstrate that the naive CD8 T cell pool is not as homogeneous as previously thought and offers a new framework for explaining the remarkable heterogeneity in the effector and memory T cell subsets that arise after infection.

COVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ~200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change.These analyses identified three "immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.