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Japanese encephalitis virus (JEV) is transmitted to humans and other animals by the bite of infected mosquitoes. A number of pig properties have recently been identified with JE virus infection. Pigs are important in JEV transmission because pigs develop high levels of viremia sufficient to infect mosquitoes (amplifying host).


There are two safe and effective vaccines for JE:

  • Imojev: Live attenuated vaccine given by subcutaneous injection. Primary course is one dose. Registered for use in people aged ≥9 months.
  • JEspect / Ixiaro: Inactivated Japanese encephalitis vaccine given by intramuscular injection. Primary course is two doses. Available for use in infants and children aged ≥2 months, immunocompromised people, and pregnant women.

NSW Health has expanded access to JE vaccine - refer to Information on people recommended to be vaccinated against Japanese encephalitis.

For more information, see the Australian Immunisation Handbook.

Current approach to vaccination in NSW

  • NSW Health has secured a limited supply of JE vaccines.
  • Vaccines are available to order from the State Vaccine Centre strictly for administration to patients in the groups recommended by CDNA. Orders are limited to ten (10) doses per clinic. Please contact your local public health unit for larger orders.

Patient investigation

  • Symptoms of JE include fever and headache, variably accompanied by neck stiffness, disorientation, tremors, coma, convulsions and paralysis. If patients present with symptoms of encephalitis, include JE in your differential diagnosis if they live or have visited rural areas, especially if they were near pig farms or report being bitten by mosquitos.
  • Refer patients with suspected JE to hospital for management and further investigation (as per alert 002/22 issued through the NSW Health Safety Alert Broadcast System).

More information

Current as at: Friday 27 January 2023
Contact page owner: Communicable Diseases