Editing COVID-19 — Origins: The Laboratory Leak Hypothesis (section)

==== The Absence of Intermediate Host ====
Every previous zoonotic coronavirus outbreak — SARS (2003), MERS (2012) — produced an identifiable animal reservoir within months of the outbreak. In SARS, palm civets were identified quickly. As of 2025, more than five years after the pandemic began, no animal with a SARS-CoV-2 progenitor virus has been found. This is unprecedented in the history of zoonotic outbreaks.