Wuhan virus and Sars are as different as cats and dogs, researchers say

SINGAPORE - Although the Wuhan virus is genetically similar to Sars, and comes from the same family, the two viruses have key differences, say researchers here.

Scientists at Singapore's Bioinformatics Institute examined a key surface protein on the Wuhan virus which binds to a receptor, allowing it to infect animals and sometimes people.

They found that it shares 76 per cent of its genetic material with Sars in this protein.

But this is a big difference, said Dr Sebastian Maurer-Stroh, deputy executive director of research at the institute, which comes under the Agency for Science, Technology and Research (A*Star).

"It's like comparing a dog and a cat," added Dr Maurer-Stroh, who is also programme director of human infectious diseases at the institute.

"It's not by any means so closely related that it's exactly like Sars."

The local researchers were asked to do the analysis by GISAID, an initiative which promotes the international sharing of all influenza virus sequences. The work was based on information from laboratories in China, Japan and Thailand, which shared information of the Wuhan virus sequence via the GISAID platform.

Like Sars and many other coronaviruses, the Wuhan virus likely originated in bats, but it is unclear yet whether there was an intermediary host before it jumped to humans.

In Sars, for instance, bats were found to be the reservoir or carrier for the virus, which then jumped to civet cats, before spreading to humans in meat markets.


Diagram of a key Wuhan virus protein, comparing the differences (in red) with the Sars virus. PHOTO: BII A*STAR

 
 
 
 

Though bats can rapidly spread pathogens that can kill humans, they somehow seem unaffected by viruses such as Ebola, Sars and Nipah. They also seem a lot hardier and live three to 10 times longer than their wingless counterparts of a similar size, like mice.

The latest analysis found the Wuhan virus was even more closely related to several coronaviruses found in bats than Sars, Dr Maurer-Stroh noted.

"But we cannot exclude the possibility that there's another animal in between," he told The Straits Times.

His laboratory is now looking at the data in more detail to tease out traits of the Wuhan virus.