Prolonged adaptive immune activation in COVID-19 implications for maintenance of long-term immunity?

Ongoing observational clinical research has prioritized understanding the human immune response to SARS-CoV-2 during the coronavirus disease 2019 (COVID-19) pandemic. Several recent studies suggest that immune dysregulation with early and prolonged adaptive immune system activation can result in cellular exhaustion. In this issue of the JCI, Files et al. compared cellular immune phenotypes during the first two months of COVID-19 in hospitalized and less severe, non-hospitalized patients. The authors utilized flow cytometry to analyze circulating peripheral blood mononuclear cells. Both patient cohorts maintained B and T cell phenotypes consistent with activation and cellular exhaustion throughout the first two months of infection. Additionally, follow-up samples from the non-hospitalized patient cohort showed that activation markers and cellular exhaustion increased over time. These findings illustrate the persistent nature of the adaptive immune system changes that have been noted in COVID-19 and suggest longer term effects that may shape the maintenance of immunity to SARS-CoV-2.

Automated summary

Observational clinical research has highlighted the immune response to SARS-CoV-2 during the COVID-19 pandemic, indicating that immune dysregulation and prolonged adaptive immune system activation can lead to cellular exhaustion. A recent study compared cellular immune phenotypes in hospitalized and non-hospitalized COVID-19 patients, revealing consistent activation and cellular exhaustion in both groups. Follow-up samples from non-hospitalized patients showed increasing activation markers and cellular exhaustion over time, suggesting potential long-term effects on immunity maintenance to SARS-CoV-2.