The new coronavirus might not be as fresh as we think. When Covid-19 emerged, a Chinese virologist ran it through a database of 500 new coronaviruses identified by the EcoHealth Alliance, an American NGO specializing in detecting new viruses and preventing pandemics. It turned out to be a hit.
“The new coronavirus corresponded to a sample taken in 2013 from a horseshoe nose bat in a cave in Yunnan Province, China,” says zoologist Peter Daszak, director of EcoHealth Alliance. “It was 96.2 percent identical.”
Intermediate host
This means that the virus was a precursor to the new coronavirus. Or a very related virus. “It is very likely that another animal has acted as an intermediate host and has thus transmitted the virus to humans,” said Daszak. “That could explain the 3.8 percent difference in the genome.”
Daszak knows what he’s talking about! The scientists of the EcoHealth Alliance hunt for viruses. Equipped with protective suits, they penetrate caves where bats stay and take samples. Direct contact with the animals’ droppings is avoided at all costs because it could expose them to some of the most dangerous yet unknown pathogens in the world—their focus: new coronaviruses.
The DNA from the samples is then compared to a public database in which all known animal viruses are collected: GenBank. This is used to check whether new viruses are involved. Scientists also use the data to predict which viruses pose the greatest danger to humans and to prevent new pandemics.
“We have already collected more than 15,000 bat samples,” said Daszak. “That has led to the identification of about 500 new coronaviruses.” This also includes the possible predecessor of the new coronavirus that causes Covid-19 and paralyzes the world.
Wild animals
Daszak estimates that bats have up to 15,000 coronaviruses among their members, of which only a few hundred are known today. EcoHealth Alliance focuses its research on China, but other virus hunters are active in other places, such as Myanmar and Kenya.
These are areas where there is a lot of biodiversities, where a growing number of people are entering the natural habitat of wild animals and where there are large amounts of livestock. That makes it ideal for places where viruses can jump from one species to another.
This is undoubtedly the case in China, according to zoologist Peter. The people there have regular contact with wild animals: they hunt them, sell them in markets, and eat them.
According to him, it is no coincidence that the new viruses usually come from bats; just think of Ebola, SARS, and Marburg. “Because bats are flying mammals, their bodies are exposed to a lot of stress. That normally triggers a reaction from their immune system, but they can suppress that. This makes the animals more susceptible to viruses and carries much higher concentrations of viruses.”
Switch
Knowing where a virus comes from and how it made the switch to humans is a critical piece of information for fighting it. It can also help prevent new coronavirus outbreaks. After all, the blood samples from bats contain antibodies that fight the virus. They can be used as a basis to make a vaccine or medicine.
