Long COVID: 'Viral reservoir' of spike protein may explain long-term symptoms

Researchers investigated the antigens of SARS-CoV-2—the virus that causes COVID-19—present in blood plasma samples collected from individuals with long COVID and typical COVID-19 infection. They found that one particular SARS-CoV-2 antigen—the spike protein—was present in the blood of a majority of long COVID patients, up to a year after they were first diagnosed with COVID-19. In patients with typical COVID-19 infection, however, the spike protein was not detected. This finding provides evidence for the hypothesis that SARS-CoV-2 can persist in the body through viral reservoirs, where it continues to release spike protein and trigger inflammation.