Could Pangolins provide a cure for Covid-19?

Researchers say Pangolins lack two of the genes that that other mammals have, to detect the entry of viruses into the body.

That is significant because, although pangolins may be carriers of coronavirus, they seem to be able to tolerate it through some other unknown mechanism and understanding why could help scientists find a cure.

Pangolins are believed to be responsible for the transmission of Covid-19 to humans, creating the jump between species required for the pandemic to gain strength.

Researchers have analysed the genome sequence of Pangolins and compared it with other mammals, including humans, cats, dogs, and livestock.

"Our work shows that Pangolins have survived through millions of years of evolution without the type of antiviral defence that all other mammals have," said Dr Leopold Eckhart of the University of Medicine in Vienna, Austria.

Further studies of Pangolins will reveal how they’ve managed to survive viral infections, and that could help researchers design new treatment strategies for people with viral infections.

Coronavirus can cause an inflammatory immune response in humans, called a cytokine storm, which makes the virus worse and the authors of the study suggest that pharmaceutical suppression of gene signalling could be a possible treatment option for severe Covid-19 cases.

But Dr Eckhart warns that such a remedy could open the door to secondary infections.

"The main challenge is to reduce the response to the pathogen whilst maintaining sufficient control of the virus. An overactive immune system can be moderated by reducing the intensity or by changing the moment of the defensive reaction,” he said. “Although the study identified genetic differences between Pangolins and other mammals, it did not investigate the impact of those differences on the antiviral response. Scientists still do not understand exactly how Pangolins survive the coronavirus, only that their lack of these two signalling genes could have something to do with it.”

Dr Eckhart acknowledged that the study is very helpful but said other routes should also be investigated.

“Another gene called RIG-I also acts as a sensor against viruses and needs to be studied more closely, because it could help defend against coronavirus," he said. "This study provides a starting point for a better understanding of coronavirus characteristics, the body's response, and the best treatment options."