Middle-aged men appear to be most at risk of catching 2019-nCoV, according to a new study.
The virus, which emerged in Wuhan, China in December, has infected at least 8000 people, killed 170 and spread to places as far away as Germany and the US.
Researchers looked at 99 of the early cases, including the first 41, to see who it was infecting.
They found two-thirds of the patients were male, and almost a third of them in their 50s. The average age was 55. Half had exposure to the Huanan seafood market, where it's believed the virus made the leap to humans.
Half of them also had underlying chronic diseases before falling sick, including cardiovascular and cerebrovascular diseases (40 patients) and diabetes (12).
All who caught the virus developed pneumonia, and most fever and a cough. Five of the 99 also suffered another infection at the same time - one bacteria and four fungi.
Seventeen of the 99 developed acute respiratory distress syndrome, and of those, 11 died.
Fifty-seven of the patients remain in hospital, and the remainder - less than a third - have been discharged.
SARS and MERS-CoV, previous outbreaks of coronaviruses related to this new one, also infected more men than women.
"The reduced susceptibility of females to viral infections could be attributed to the protection from X chromosome and sex hormones, which play an important role in innate and adaptive immunity," the study - published in The Lancet - said.
"Our results suggest that 2019-nCoV is more likely to infect older adult males with chronic comorbidities as a result of the weaker immune functions of these patients."
SARS' mortality rate was about 10 percent. Though 2019-nCoV so far appears to have a mortality rate of between 2 and 3 percent, 11 of the 99 patients looked at in this study died - and the researchers say more deaths could still come, with more than half of the group still in hospital.
The researchers say it's still early days, and they'll have a better understanding of who's most at risk as more patients are infected.
The World Health Organization (WHO) on Friday declared a global health emergency in an attempt to avoid this happening.
"So far we have not seen any deaths outside China, for which we must all be grateful," said WHO director-general Tedros Adhanom Ghebreyesus. "Although these numbers are still relatively small compared to the number of cases in China, we must all act together now to limit further spread."
No confirmed cases have been identified in New Zealand yet.
"The speed with which China detected the outbreak, isolated the virus, sequenced the genome and shared it with WHO and the world are very impressive - so is China's commitment to transparency and to supporting other countries," said Dr Tedros.
"In many ways China is actually setting a new standard for outbreak response."
