This vaccination is usually given for rural travel and is a viral infection usually transmitted by mosquitoes with the host being pigs and wading birds. Infection can cause swelling of the brain leading to permanent brain damage and death.

In tropical countries the risk of infection is consistent year-round, however in temperate countries the risk is increased during the rainy seasons.

Signs and symptoms usually occur 5-15 days after a mosquito bite and include:

• Flu-like symptoms
• Fever
• Confusion
• Convulsions
• Neck stiffness and paralysis

Vaccination is usually given as two vaccines over 28 days.