Pangolins were called the missing link in the transmission of coronavirus from bats to humans. This conclusion was made by scientists from the American Chemical Society, a study of which was published in the journal Journal of Proteome Research.
Understanding where SARS-CoV-2 came from – the virus that caused the COVID-19 pandemic – and how it spreads, is important in order to control and treat it. Most experts agree that bats are a natural reservoir of SARS-CoV-2, but an intermediate host was needed to transfer the virus from bats to humans.
In two recently published studies on the analysis of the genome of the virus, scientists concluded that snakes are intermediate hosts of the new virus and that the key protein of coronavirus has a “strange resemblance” to the HIV-1 protein. After a wave of criticism from the scientific community, the authors removed the preprint of the study from publication in a scientific journal.
In a new study, scientists refute these findings – they performed a “more thorough and complete” analysis of DNA sequences and SARS-CoV-2 proteins. The analysis showed that four protein sections were uniquely distributed between SARS-CoV-2 and HIV-1, and four segments of the sequence could be detected in other viruses, including bat coronavirus.
The researchers then searched for DNA sequences and proteins isolated from pangolin tissues for similarities with SARS-CoV-2. The analysis showed that the protein sequences in the lungs of sick animals are 91% identical to the human virus protein sequences.
“These data indicate that pangolin is the most likely intermediate host for the new coronavirus, but additional intermediate hosts are possible”.
Chenxin Zhang, lead author of the study