Japanese Encephalitis

Japanese encephalitis is a viral infection spread by mosquitoes in parts of Asia and the Western Pacific. Most infections are mild, but in rare cases it can cause severe brain inflammation, which may be life-threatening or lead to long-term complications.

Most people tolerate the vaccine well. The most common side effects are soreness at the injection site, mild fever, or headache. These usually settle within a day or two. Serious side effects are very rare.

The vaccine is given as two doses, usually spaced 28 days apart. For those needing rapid protection, an accelerated schedule may sometimes be used.

Once the course is complete, protection lasts for at least 1–2 years. A booster may be recommended for ongoing risk.