Plasma-based antigen persistence in the post-acute phase of COVID-19

We used an ultra-sensitive experimental assay on the blood of 171 participants previously infected with COVID-19 and 250 participants whose blood was collected prior to the COVID-19 pandemic to look for the presence of the spike protein of the COVID-19 virus. While pieces of the COVID-19 virus are common throughout the body when people first test positive for COVID-19, it was previously thought that these particles would be long gone after that period (which lasts a couple weeks). In this study, however, we found evidence of the COVID-19 spike protein in the blood of post-COVID-19 infected participants up to 14 months after their original infection. Those who were hospitalized or had more severe COVID-19 infections had greater levels of COVID-19 spike protein as well. It’s possible that this persistence of viral material could be contributing to the continuing symptoms associated with Long COVID.