Pangolins naturally host coronaviruses, but evidence does not support their role in transmitting SARS-CoV-2 to humans.
Bats are likely the primary reservoir for SARS-CoV-2, the virus behind the COVID-19 pandemic. However, these viruses in bats lack the receptors needed to directly infect humans, pointing to an intermediate host. Identifying this host is crucial for effective disease control and preventing future outbreaks.
Pangolins have drawn scrutiny due to decades of human contact through illegal trade for their scales, prized in traditional medicine. But did they serve as the bridge?
A study published in late March in Nature examined samples from 18 Malayan pangolins seized in anti-smuggling operations in southern China from August 2017 to January 2018. Coronaviruses related to SARS-CoV-2 were found in five samples.
Yet, the genetic similarity was insufficient to confirm pangolins as the direct source of human transmission. A follow-up genetic analysis by researchers at China's Guangdong Institute of Applied Biological Resources reinforces this.
Published in PLOS Pathogens, this research sequenced the genome of a coronavirus from three deceased Malayan pangolins rescued from China's black market by the Guangdong Wildlife Rescue Center.
The virus shares genetic similarities with SARS-CoV-2 and bat coronaviruses like BatCoV-RaTG13, but is unlikely to be its direct precursor.
Sequence identity stood at 90.32% with SARS-CoV-2 and 90.24% with BatCoV-RaTG13 from Rhinolophus affinis bats—the closest known relative at 96.18% match to SARS-CoV-2.
These findings do not position pangolins as the key intermediate host for SARS-CoV-2 emergence. Still, other unidentified coronaviruses may circulate in these natural carriers.
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