# Japanese Encephalitis

> The content on this page is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment recommendations. If you have health concerns, consult a qualified healthcare professional. Medova is not a medical service provider.

Source: https://medova.health/en/knowledge/vaccines/japanese-encephalitis · Language: en

## Vaccine Information

- Type: Inactivated
- Administration: Injection
- WHO Code: JE
- Travel Recommended: Yes

**Pregnancy: Limited data — use only if risk is high.**

Limited safety data for Ixiaro (inactivated Vero cell vaccine) in pregnancy.


- Administer only if the risk of Japanese encephalitis exposure is judged to be high (prolonged rural travel during transmission season in endemic Asia).

- No teratogenic effects reported in animal studies.

- Live attenuated JE formulations (SA14-14-2, Imojev): contraindicated in pregnancy.

- Defer vaccination until after delivery whenever possible.

**Breastfeeding: Limited data — likely safe.**

No formal studies of Ixiaro during breastfeeding. As an inactivated vaccine, it is unlikely to pose a risk to the breastfed infant. CDC considers inactivated vaccines generally acceptable during breastfeeding.

**Pediatric use:**


- **Ixiaro:** licensed from **2 months** of age.
  - 2 months to <3 years: 0.25 mL IM per dose.
  - ≥3 years: 0.5 mL IM per dose.
  - 2 doses on days 0 and 28. Accelerated schedule (days 0 and 7) available for adults ≥18 years only.

- Booster: 1 dose ≥1 year after primary series if ongoing exposure risk.

- **Live attenuated SA14-14-2 (in endemic countries):** single dose from 8 months of age.

**Geriatric use:**


- No specific dose adjustment required.

- Immune response may be slightly lower in elderly adults — consider booster if ongoing exposure risk.

- Japanese encephalitis is more severe in older adults (higher case-fatality rate in ≥65 years).

- Standard 2-dose Ixiaro schedule applies.

## Side Effects

- Abdominal pain (Uncommon)
- Anaphylaxis (Very rare) — Serious
- Angioedema (Very rare) — Serious
- Arthralgia (Common)
- Chills (Uncommon)
- Diarrhea (Common)
- Dizziness (Uncommon)
- Drowsiness (Very common)
- Excessive crying (Very common)
- Fatigue (Very common)
- Febrile seizure (Rare) — Serious
- Fever (Common)
- Generalized rash (Uncommon)
- Headache (Very common)
- Injection site induration (Common)
- Injection site itching (Common)
- Injection site pain (Very common)
- Injection site redness (Common)
- Injection site swelling (Common)
- Insomnia (Uncommon)
- Irritability (Very common)
- Loss of appetite (Very common)
- Lymphadenopathy (Uncommon)
- Malaise (Common)
- Myalgia (Very common)
- Nausea (Common)
- Paresthesia (Rare)
- Pruritus (Uncommon)
- Urticaria (Uncommon)
- Vomiting (Common)

## Contraindications

- Acute febrile illness (Precaution)
- Age below minimum recommended (Absolute)
- Anaphylaxis after previous dose (Absolute)
- Allergy to vaccine component (Absolute)
- Bleeding disorder (Precaution)
- History of Guillain-Barré syndrome (Precaution)
- Latex allergy (Relative)
- Moderate immunosuppression (Precaution)
- Pregnancy (Relative)
- Thrombocytopenia (Precaution)

## Vaccination Schedule

No schedule data available.

## FAQ

**What are the side effects of Japanese Encephalitis?**

Common side effects include: Abdominal pain, Anaphylaxis, Angioedema, Arthralgia, Chills.

**Who should not get Japanese Encephalitis?**

Contraindications include: Acute febrile illness, Age below minimum recommended, Anaphylaxis after previous dose, Allergy to vaccine component, Bleeding disorder.

**What is the Valneva vaccine (IXIARO)?**

IXIARO is a Japanese Encephalitis vaccine manufactured by Valneva. It is an inactivated vaccine recommended for travelers to endemic areas in Asia and the Western Pacific.

**Which travel destinations require IXIARO?**

IXIARO is recommended for travelers spending extended time in rural areas of Southeast Asia, East Asia, and the Indian subcontinent, especially during monsoon season. Countries include India, Thailand, Vietnam, Cambodia, Myanmar, Indonesia, Philippines, China, and Japan.

**How many doses of IXIARO do I need?**

The standard IXIARO schedule is 2 doses given 28 days apart, with the second dose at least 1 week before travel. A booster dose is recommended after 12-24 months for continued protection.

## Prevents

- [Japanese Encephalitis](https://medova.health/en/knowledge/diseases/japanese-encephalitis)

## Indications

- [Vietnam](https://medova.health/en/knowledge/countries/vietnam): Recommended
- [Myanmar](https://medova.health/en/knowledge/countries/myanmar): Recommended
- [Malaysia](https://medova.health/en/knowledge/countries/malaysia): Recommended
- [Indonesia](https://medova.health/en/knowledge/countries/indonesia): Recommended
- [Indonesia](https://medova.health/en/knowledge/countries/indonesia): Recommended
- [Indonesia](https://medova.health/en/knowledge/countries/indonesia): Recommended
- [Indonesia](https://medova.health/en/knowledge/countries/indonesia): Recommended
- [Vietnam](https://medova.health/en/knowledge/countries/vietnam): Recommended
- [Vietnam](https://medova.health/en/knowledge/countries/vietnam): Recommended
- [Vietnam](https://medova.health/en/knowledge/countries/vietnam): Recommended

## Sources & content verification

- Data sources: WHO Position Papers 2024 + CDC Pink Book 2024 + EMA SmPC
- [www.who.int](https://www.who.int/teams/immunization-vaccines-and-biologicals/policies/position-papers)

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The content on this page is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment recommendations. If you have health concerns, consult a qualified healthcare professional. Medova is not a medical service provider.

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