Scientists detect virus traces in blood that may unlock long COVID’s mystery

Scientists have found protein fragments from the COVID-19 virus hidden inside tiny cellular packages in the blood of long COVID patients, offering the first potential measurable biomarker for the condition. The discovery suggests the virus may persist in body tissues long after infection, possibly explaining ongoing symptoms. While promising, the signals were subtle and inconsistent, leaving unanswered questions about whether these fragments come from lingering viral reservoirs or active replication.