Immune Dysfunction Persists For Up To 8 Months After Initial Mild Or Moderate SARS-CoV-2 Infection

A new study by researchers from The Kirby Institute at the University of New South Wales-Australia, St Vincent’s Hospital, Darlinghurst, New South Wales-Australia, University of Melbourne-Australia and Monash University-Australia has found that immune dysfunction persists for up to 8 months after initial mild or moderate SARS-CoV-2 infection. 

The study findings were published in the peer reviewed journal: Nature Immunology.
https://www.nature.com/articles/s41590-021-01113-x
A proportion of patients surviving acute coronavirus disease 2019 (COVID-19) infection develop post-acute COVID syndrome (long COVID (LC)) lasting longer than 12 weeks. Here, we studied individuals with LC compared to age- and gender-matched recovered individuals without LC, unexposed donors and individuals infected with other coronaviruses.

Patients with LC had highly activated innate immune cells, lacked naive T and B cells and showed elevated expression of type I IFN (IFN-β) and type III IFN (IFN-λ1) that remained persistently high at 8 months after infection. Using a log-linear classification model, we defined an optimal set of analytes that had the strongest association with LC among the 28 analytes measured.

Combinations of the inflammatory mediators IFN-β, PTX3, IFN-γ, IFN-λ2/3 and IL-6 associated with LC with 78.5–81.6% accuracy. This work defines immunological parameters associated with LC and suggests future opportunities for prevention and treatment.