Residents in the Upper Hunter local government area can now receive a free Japanese encephalitis vaccine, with the area being designated a risk for the disease.
NSW Health has expanded access to the free vaccine to a further 14 areas that border existing eligible areas in regional NSW.
This includes residents living or working regularly in the Hunter New England areas of Gunnedah, Gwydir, Inverell, Liverpool Plains, Tamworth and Tenterfield.
The Upper Hunter is the only area in the Hunter to be eligible.
Eligibility criteria for the vaccine is: those who regularly spend time outdoors, are homeless or live in tents, caravans or dwellings with no insect screens.
The vaccine is also for those who participate in prolonged outdoor flood recovery efforts, such as clean-ups.
Dr Peter Murray, Hunter New England Health's acting public health director, said eligibility was expanded after "health and environmental experts carefully considered surveillance data from the past two mosquito seasons".
Dr Murray said a dry and hot summer with fewer mosquitoes was expected.
However, experts determined that "until ecological and climate factors behind Japanese encephalitis transmission were better understood, it was important to expand eligibility" to the vaccine.
He encouraged eligible people at greater risk of mosquito bites to consider vaccination.
The vaccine can be obtained through GPs, pharmacists and Aboriginal Medical Services.
Japanese encephalitis was "a serious disease", but Dr Murray noted that about one per cent of people infected with the virus will experience symptoms.
NSW Health data shows only one case of the disease from October 2022 to April 2023 in Lachlan in the Central West.
Thirteen cases and two deaths occurred in NSW from October 2021 to April 2022.
Infected mosquitoes spread the disease to humans. People can't pass the virus to each other.
Humans cannot get infected with the virus by touching an infected animal or eating animal products.
Dr Murray said mosquitoes in NSW "can carry a range of viruses, including Murray Valley encephalitis virus, Kunjin virus, Ross River virus, Barmah Forest virus, as well as JE [Japanese encephalitis] virus".
"Vaccine is only available for JE, so avoiding mosquito bites is the most important way of preventing these infections," he said.
He said the key to protection against mosquito borne infections was avoiding mosquito bites.
Protection measures include: covering windows and doors with insect screens and blocking gaps; removing items that collect water such as old tyres and empty pots; improving drainage on your property so water does not become stagnant.
Other measures include: wearing light, loose-fitting long-sleeved shirts, long pants and covered footwear and socks, especially around dusk and dawn; applying repellent to all areas of exposed skin, using repellents that contain DEET, picaridin or oil of lemon eucalyptus.
Use of insecticide sprays, vapour dispensing units and mosquito coils to repel mosquitoes were also recommended.