NSW Health experts have successfully grown the coronavirus from an infected patient, with samples to assist efforts make a vaccine for the deadly disease.

Health experts in NSW are hopeful their success in growing the coronavirus from infected patients will help global efforts to develop a vaccine for the virus.

NSW Health pathology director Professor Dominic Dwyer said the team of 10 scientists and pathologists isolated the live virus from patients and then sequenced it at Westmead Hospital.

"Our tests are working well and we can also make a contribution in understanding how the virus is changing around the world," he told reporters in Sydney on Monday.

"By having an isolate we can help other laboratories in NSW and elsewhere to develop the right tests and potentially can help vaccine manufacturers by providing viruses they can work on to hopefully eventually develop a vaccine."

Of the four confirmed cases in NSW, one patient - a 43-year-old man - remains in Westmead Hospital with scientists being able to gather regular samples from the man for their research.

Prof Dwyer hopes the samples will help scientists understand why some coronavirus patients get more sick and develop a severe lung illness while most patients have a mild sickness.

NSW's breakthrough follows the same discovery by researchers at the Peter Doherty Institute for Infection and Immunity in Melbourne who were the first scientists outside China to recreate the virus.

The genetic sequences will go into a global bank run by the World Health Organisation to help improve the detection and confirmation of cases and to support the development of an effective treatment and vaccine.

NSW Health Minister Brad Hazzard described it as an "incredible" result which he hopes will help the WHO.

Mr Hazzard said 14,500 people have been screened for coronavirus at Sydney airport since February 2 with 57 showing symptoms that needed further testing. All were cleared.

NSW chief health officer Dr Kerry Chant insisted it's safe to be out and about and that she had "no qualms" walking around by herself or with her family.