Disease & Vaccine A–Z

Diseases beginning with J

U.S.-focused summaries with current official guidance links. For a diagnosis, personal vaccine schedule, pregnancy advice, or urgent symptoms, speak with a qualified clinician.

Japanese Encephalitis

Travel vaccine

Disease

A mosquito-borne virus found mainly in parts of Asia and the western Pacific.

Symptoms

Most infections have no symptoms; severe disease can cause fever, headache, vomiting, confusion, seizures, weakness, or coma.

Typical duration

Symptoms generally begin five to 15 days after infection; neurologic recovery can take months and may be incomplete.

How serious is it?

Encephalitis is rare but can be fatal or leave permanent neurologic disability.

Treatment & management

No specific antiviral treatment; severe disease requires hospital supportive care.

Vaccine: who and when?

Product: IXIARO, a two-dose inactivated vaccine for travelers and laboratory workers at risk. The second dose is normally 28 days after the first; eligible adults ages 18-65 may use an accelerated day 0 and day 7 schedule. Complete the series at least one week before travel; a booster may be needed for continued risk.

Check the current CDC guidance for Japanese Encephalitis →

Cost and access: Patient cost varies by insurance, provider, location, and eligibility. Many recommended vaccines are covered with no out-of-pocket cost under qualifying plans, and eligible children may receive vaccines through the Vaccines for Children program. CDC price lists are purchasing benchmarks—not guaranteed patient prices. CDC price and program context.

Last reviewed against official U.S. sources: September 5, 2026. This page provides general education, not medical advice.