Within weeks, it has spread to several countries and has killed multiple people.

Corona refers to the virus's distinctive shape.

They are a large group, common among mammals and birds.

But in rare cases like this one, they can spread to humans - a process known as zoonosis.

This new virus is the seventh known human coronavirus,

and it affects the respiratory system.

Some coronaviruses have mild symptoms; however, others are much more dangerous.

SARS and MERS are both coronaviruses.

The most urgent question is how does it spread?

It seems that the virus can be transmitted between humans, but it's still unclear whether this happens routinely.

Some early severe cases caused a lot of concern, but this has receded slightly, as more mild cases turn up.

The new virus does not seem to be as deadly as SARS, which killed around 11 percent of the people it infected.

Researchers think that the virus originated in an unknown animal at a market in Wuhan.

Identifying that animal could help control the current outbreak and gauge its threat going forward.

The virus's genetic code could offer clues to its origins and spread.

Labs in China and Thailand have sequenced at least 19 strains from infected people, and made them publicly available.

Analysis is ongoing.

There are no known drugs that can effectively treat coronavirus infections in humans, and no vaccines are currently licensed.

But researchers are working on the problem.

One possible avenue is to block the receptor the viruses use to infect humans.

With more cases being reported every day, the race is on to contain the outbreak.

And scientists are at the heart of the effort.