A veteran paramedic who finds all COVID-19 vaccines "morally repugnant" due to his religious, moral and political views faces termination for a temporary "storm", a judge has been told.
Tumut paramedic John Larter wants the NSW Supreme Court to scrap a vaccine mandate for healthcare workers or otherwise exempt him from following it.
"The plaintiff is an adherent to the Roman Catholic faith and considers himself to be a political conservative," Shane Prince SC, for Mr Larter, said on Thursday
"It's his religious, moral and political views that makes him feel he is unable to take the vaccine as he finds it morally repugnant. That is the contentious objection."
Mr Prince argues it wasn't reasonable that workers could be terminated with permanent effect for the temporary pandemic.
"Even when the storm passes, they're no longer part of Health," he said.
About 93.7 per cent of NSW residents aged over 16 have received at least one jab, including 97 per cent of NSW Health workforce.
That leaves about 5000 state-employed health workers such as Mr Larter unvaccinated.
NSW's chief health officer, Dr Kerry Chant, said some exemptions will have been granted to unvaccinated workers who recently recovered from COVID-19 and the "very few" who have medical contraindications.
The interconnectivity of the health system and the high vulnerability of patients within it meant the vaccine mandate played a major role in limiting the spread of the virus, she told the court.
Mr Prince repeatedly pressed Dr Chant to answer what risk a small number of conscientious objectors posed among an overwhelmingly vaccinated workforce.
"It's right to say you've done no modelling, no statistical analysis and there's no projection of what impact on the public health allowing a small number of conscientious objectors to remain as healthcare workers would have, have you?" he asked.
"There are too many variable inputs to really meaningfully do that modelling," Dr Chant replied.
Justice Christine Adamson, who will continue hearing the case on Friday, questioned whether an unvaccinated healthcare worker was "like a wolf, and the lambs are to the slaughter".
"According to the science, which isn't challenged ... (the worker) is going to be more susceptible to getting it themselves and also passing it onto others," she said.
"The key thing in Your Honour's analogy is the wolf must be among the sheep," Mr Prince said, maintaining his argument that NSW Health could and should find other duties for Mr Larter that don't require interaction with patients.
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.