The NSW Supreme Court on Wednesday dismissed a case by John Larter to overturn a public health order preventing healthcare workers from working if not fully vaccinated by November 30.

The Tumut paramedic and local councillor finds the COVID-19 vaccines "morally repugnant" due to his Roman Catholicism, morality and conservative political views, his lawyer told the court last week.

It was accepted that those views, grounded in concerns about stem cell research, departed from those of the Church, which says vaccines are "morally acceptable", and Pope Francis, who is himself vaccinated.

Mr Larter had argued the court should invalidate the NSW law for several reasons, including that it was unreasonable for unvaccinated workers to be terminated for a temporary pandemic.

But Justice Christine Adamson said the ambit of the order was reasonable.

She based that on reasons offered by Chief Health Officer Kerry Chant, including that the virus was high risk and easily transmitted, NSW Health operated an integrated system, and the vaccine was relatively inefficacious for vulnerable people.

While the risk of an unvaccinated healthcare worker catching and passing the virus might be regarded as relatively remote, the harm - such as deaths and operational disruption to hospitals - also needed to be considered, the judge said.

"It would be of no comfort to the vulnerable patient who is infected by the unvaccinated health care worker to be told that he or she was unlucky by being in the wrong ward at the wrong time because most health care workers had been vaccinated," Justice Adamson said.

She said it was reasonably open for Health Minister Brad Hazzard to make the orders on the basis of Dr Chant's advice.

The effect of not being vaccinated could be "grave and potentially far-reaching and permanent" but that was the inevitable consequence of the minister's powers, his decision and the risk posed by the virus, the judge said.

As at October 22, 4995 NSW Health employees (2.7 per cent) were unvaccinated, while about 172,000 (93 per cent) were fully vaccinated.

The unvaccinated group included Mr Larter and 154 other ambulance staff.

Mr Larter is currently on paid sick leave.

The challenge comes after 10 unvaccinated workers unsuccessfully tried to overturn a public health order that required teachers, nurses and certain Sydney residents to be vaccinated to work.

In that case, Justice Robert Beech-Jones found the applicable orders were not vaccine mandates per se but were restrictions on movement.

Australian Associated Press