IXIARO: A Vaccine for Japanese Encephalitis

IXIARO is an inactivated vaccine designed to prevent Japanese encephalitis (JE), a viral infection caused by the Japanese encephalitis virus (JEV). JE is primarily spread through the bite of infected mosquitoes, especially in rural and agricultural regions of Asia and the Western Pacific. This vaccine is crucial for travelers, military personnel, and individuals living in JE-endemic areas who are at risk of infection. The vaccine is typically administered as a two-dose series.

How IXIARO Works

Mechanism of Action:

1. Inactivated Virus:
   • IXIARO contains an inactivated form of the Japanese encephalitis virus. Since the virus is killed, it cannot cause the disease.
2. Immune System Stimulation:
   • When administered, the vaccine introduces the inactivated virus into the body. The immune system recognizes the viral proteins as foreign and mounts an immune response.
3. Antibody Production:
   • The immune system responds by producing antibodies against the viral proteins. These antibodies are specific to the Japanese encephalitis virus and are essential for protection.
4. Memory Response:
   • The vaccine also stimulates the formation of immune memory cells, which remember the virus. If the vaccinated individual is later exposed to the live virus, these memory cells quickly respond, producing antibodies to neutralize the virus and prevent infection.
5. Long-Term Protection:
   • While protection duration varies, the immune response from IXIARO typically provides protection for several years, reducing the risk of severe neurological complications associated with JE.

Combined Effect:

Overall, IXIARO trains the immune system to recognize and defend against the Japanese encephalitis virus, providing critical protection against this potentially fatal disease.

Side Effects

Like all vaccines, IXIARO can cause side effects, though most are mild and resolve on their own. Severe side effects are rare.

Common Side Effects:

• Pain at the Injection Site
• Swelling and Redness at the Injection Site
• Fever
• Headache
• Muscle Pain
• Fatigue
• Nausea

Rare Side Effects:

• Severe Allergic Reactions (anaphylaxis)
• Dizziness
• Skin Rash
• Joint Pain
• Vomiting

Indications

IXIARO is indicated for active immunization against Japanese encephalitis. It is primarily recommended for:

Approved Indications:

• Travelers to JE-Endemic Areas: Individuals traveling to rural areas of Asia and the Western Pacific, particularly during the transmission season.
• Military Personnel: Deployed to regions with a risk of JE exposure.
• Residents of Endemic Areas: People living in areas where JE is prevalent, especially if they are at higher risk of mosquito exposure.
• Laboratory Workers: Those working with the Japanese encephalitis virus or infected animals.
• Expatriates and Long-Term Visitors: Staying in JE risk areas for prolonged periods.

Contraindications

While IXIARO is generally safe, it is contraindicated in certain conditions where the risks outweigh the benefits.

Contraindications:

• Hypersensitivity: Individuals with a known allergy to any component of the vaccine, including protamine sulfate.
• Severe Allergic Reaction to a Previous Dose: History of anaphylaxis or severe allergic reaction to any previous dose of IXIARO.
• Acute Febrile Illness: Vaccination should be postponed in individuals with an acute illness accompanied by fever until recovery.
• Pregnancy and Breastfeeding: Should be administered only if the potential benefits justify the potential risks to the fetus or infant.
• Immunocompromised Individuals: Those with weakened immune systems due to illness or medication may not develop an adequate immune response.

Price in Different Countries

The cost of IXIARO varies widely across different countries, influenced by healthcare systems, availability, and distribution channels. Below is a table showing the approximate prices in various countries.

Country	Price (Per Dose)	Reference
United States	$320 – $350	GoodRx
United Kingdom	£100 – £150	NHS UK
Australia	AUD $280 – $320	PBS Australia
Canada	CAD $400 – $450	Health Canada
India	₹12,000 – ₹15,000	1mg

Top 5 Global Brands

Several global pharmaceutical companies produce and distribute vaccines for Japanese encephalitis. Below are the top brands recognized globally:

1. Valneva SE

• Manufacturer of IXIARO, Valneva is a specialty vaccine company focused on developing and commercializing vaccines for infectious diseases. IXIARO is their leading product for JE prevention.

2. Sanofi Pasteur

• Sanofi Pasteur, a major player in the vaccine industry, produces JE-VAX and IMOJEV, two other vaccines for Japanese encephalitis widely used in endemic areas.

3. Green Cross Corporation

• A South Korean biopharmaceutical company that produces vaccines, including those for Japanese encephalitis, distributed throughout Asia.

4. Chengdu Institute of Biological Products Co., Ltd.

• This Chinese institute manufactures live attenuated vaccines for JE, contributing to mass immunization programs in Asia.

5. GPO-MBP (Government Pharmaceutical Organization – Merieux Biological Products)

• Based in Thailand, this joint venture produces JE vaccines primarily for local and regional use in Southeast Asia.