Japanese Encephalitis: Symptoms, Treatment & Vaccine Guide

← Diseases beginning with J
Travel vaccine

Japanese Encephalitis

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

SymptomsMost infections have no symptoms; severe disease can cause fever, headache, vomiting, confusion, seizures, weakness, or coma.
Typical durationSymptoms generally begin five to 15 days after infection; neurologic recovery can take months and may be incomplete.
Vaccine statusTravel vaccine

Symptoms and what to notice

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

How long can it last?

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

How serious is Japanese Encephalitis?

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

Treatment and management

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

Is there a vaccine—and who should receive it?

IXIARO is a two-dose U.S. vaccine for eligible travelers and laboratory workers. Dose spacing is age-dependent; complete the series at least one week before travel.

Official U.S. guidance

Read the current CDC guidance for Japanese Encephalitis →

Cost: 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 context.

Health note: This page gives general U.S. educational information. Vaccine choice and timing depend on age, medical history, previous doses, pregnancy, travel, exposure, and current public-health guidance. Seek urgent care for severe or rapidly worsening symptoms.