Since relatively early in the COVID-19 pandemic, there has been a recognition that in some people, SARS-CoV-2 — or at least remnants of the virus — could stay in various tissues and organs for extended periods. This theory is known as “viral persistence”.

While the long-term presence of residual viral fragments in some people’s bodies is now well established, what remains less certain is whether the live virus itself, not just old bits of virus, is lingering — and if so, whether this is what causes Long COVID.

This distinction is crucial because live viruses can be targeted by specific antiviral approaches in ways that “dead” viral fragments cannot.