Maria Van Kerkhove, head of WHO's emerging diseases and zoonosis unit, said scientists have observed "normal changes" in the virus, which were expected.

"To date, to my knowledge, we haven't seen any particular signal in the virus' behavior or in its sequence that would lead us to believe the virus is changing in its nature, has changed in its transmission dynamics, or changed in its lethality," he added.

RNA viruses like the coronavirus mutate more quickly than some other viruses, Ryan said, because unlike human DNA, RNA viruses do not have "natural error checking," meaning that the code of the virus cannot correct itself.

For the time being, though, the virus is "relatively stable," Van Kerkhove said.

That doesn't mean the virus won't become more dangerous with time, Van Kerkhove said, adding that it won't necessarily be due to a mutation.

She said that if people or governments become complacent about responding to the virus, it will become more dangerous.