Many People with Long COVID Have Signs of Persistent SARS-CoV-2 Proteins, New Findings Show
Objective
Discussion
The findings of this multicohort study indicate that SARS-CoV-2 antigens can be detected in the blood of a substantial proportion of individuals up to 14 months after infection. While approximately one in five asymptomatic individuals was antigen-positive, roughly half of all individuals reporting ongoing cardiopulmonary, musculoskeletal, and neurologic symptoms were antigen-positive.
While the researchers can’t definitively show that persistent infections are the cause of some Long COVID symptoms, the findings add to growing evidence that low levels of viral protein being present may explain some but not all cases of Long COVID. The authors and many other researchers suspect that Long COVID likely has multiple underlying causes. For instance, it’s possible that the virus may lead to harmful changes in the immune system that play a role in some cases of Long COVID.
Scientists also want to see if there is a subset of people with Long COVID or persistent symptoms who may benefit from antiviral treatment. To this end, RECOVER is supporting a clinical trial evaluating whether the antiviral drug Paxlovid (a combination of nirmatrelvir and ritonavir), which is used to treat COVID-19, could also be used to improve Long COVID symptoms. The trial is using the SARS-CoV-2 blood test developed by the Brigham and Women’s study team to evaluate whether Paxlovid can eliminate viral proteins from participants’ blood.
More study is needed to understand the causes of Long COVID symptoms in people who test negative for persistent infection, the researchers note. They are conducting follow-up studies in even more people with Long COVID, including those with compromised immune systems. They hope to learn more about what causes some people to be at higher risk for retaining some SARS-CoV-2 protein remnants and Long COVID.