Vaccine Info

Ixiaro Japanese Encephalitis Vaccine

Authored by
Staff
Last reviewed
September 3, 2021
Fact checked by
Robert Carlson, MD
Share

Ixiaro Vaccine Description

Valneva SE's Ixiaro is an inactivated, adsorbed Vero cell culture-derived vaccine targeted against the Japanese encephalitis virus (JEV). It is prepared by propagating JEV strain SA14-14-2 in Vero cells. Multiple viral harvests are pooled, clarified, and concentrated. The virus suspension is treated with protamine sulfate to remove contaminating DNA and proteins.

The resulting partially purified virus is processed through a sucrose density gradient centrifugation step and fractionated. Each fraction is analyzed for the presence of the virus, and fractions with the highest virus activity are pooled to give a purified virus suspension. The purified virus is then inactivated by treatment with formaldehyde. The preparation is adjusted to a specified protein concentration and formulated by the addition of aluminum hydroxide.

France-based Valneva SE's IXIARO is the only vaccine approved by the U.S. FDA against JV. The IXIARO vaccine was developed through a cooperative research and development agreement with the Walter Reed Army Institute of Research. Valneva markets and distributes IXIARO® directly to the U.S. military and U.S. private market.

The Ixiaro vaccine was Approved on March 30, 2009. Currently, Ixiaro is licensed in Australia, New Zealand, Europe, Canada, Switzerland, Hong Kong, Singapore, and Israel.

Visit PreventJE.com, a website for travel health professionals and their patients, focusing on the risk and prevention of Japanese encephalitis for travelers to Asia.

Valneva SE (Nasdaq: VALN; Euronext Paris: VLA) is a specialty vaccine company focused on the prevention against diseases with major unmet needs. For more information, visit www.valneva.com. Valneva USA, Inc. is located at 910 Clopper Road, Suite 160S, Gaithersburg, MD 20878, USA.

Ixiaro Vaccine Indication

The JE virus is the leading cause of vaccine-preventable encephalitis in Asia and the western Pacific. Japanese encephalitis is a deadly infectious disease. JE is fatal in approximately 30% of those who show symptoms and leaves half of the survivors with permanent brain damage. In 2005, JE killed more than 1,200 children in only one month during an epidemic outbreak in Uttar Pradesh, India, and Nepal.

For most travelers to Asia, the risk for JE is very low but varies based on the destination, length of travel, season, and activities. Ixiaro is indicated for active immunization to prevent disease caused by the Japanese encephalitis virus and is approved for use in individuals 2 months of age and older.

Immunocompromised individuals may have a diminished immune response to IXIARO®. Syncope can occur in association with the administration of injectable vaccines, including IXIARO®. Procedures should be in place to prevent injury from falling and manage syncopal reactions.

Vaccination with IXIARO may not protect all individuals. Immunocompromised individuals may have a diminished immune response to IXIARO. In addition, syncope can occur in association with the administration of injectable vaccines, including IXIARO. Procedures should be in place to prevent injury from falling and manage syncopal reactions.

Ixiaro Vaccine Side Effects

Severe allergic reaction (e.g., anaphylaxis) after a previous dose of IXIARO®, any other Japanese encephalitis vaccine, or any component of IXIARO®, including protamine sulfate ─ a compound known to cause hypersensitivity reactions in some individuals ─ is a contraindication to administration of IXIARO®. Individuals with a history of severe allergic reaction to another Japanese encephalitis vaccine may be referred to an allergist for evaluation if immunization with IXIARO® might be considered.

The most common ( > 10%) adverse reactions were: fever, irritability, diarrhea, and injection site redness in infants 2 months to < 1 year of age; fever in children 1 to < 12 years of age; pain and tenderness in adolescents 12 to < 18 years of age; and, headache, myalgia, and injection site pain and tenderness in adults.

Ixiaro Vaccine Dosage

Ixiaro is administered as an intramuscular injection and is approved for use in individuals 2 months of age and older. In 2019, the U.S. CDC's ACIP committee strengthened its language on booster doses to say they should be given at least 1 year after the primary series if the person is experiencing ongoing exposure or re-exposure to the JE virus.   

Primary Series: Children 2 months to <3 years of age: Primary immunization with IXIARO consists of two (2) 0.25 mL doses, administered 28 days apart; Individuals 3 years of age and older: Primary immunization with IXIARO consists of two (2) 0.5 mL doses, administered 28 days apart; Complete the primary immunization series at least 1 week before potential exposure to JEV.

Booster Dose: Individuals 17 years of age and older: If the primary series of two doses was completed more than 1 year previously, a booster dose might be given if ongoing exposure or re-exposure to JEV is expected; Infants, children, and adolescents 2 months to <17 years of age: The safety and immunogenicity of a booster dose have not been evaluated.

Ixiaro Vaccine News

September 3, 2021 - Valneva SE announced that the U.S. Department of Defense (DoD) had exercised the first option of the contract signed in September 2020 to purchase a further supply of its Japanese encephalitis vaccine IXIARO®. Due to the ongoing impact of the COVID-19 pandemic on DoD operations, the option terms have been amended such that the minimum number of doses for the first option year is now 200,000 with an approximate value of $28.8 million. This brings the total minimum value of the contract to approximately $118 million, assuming the exercise of the second-year option, which remains unchanged, compared to a minimum value of $135 million in the initial contract.

August 10, 2021 - Valneva SE reported sales of IXIARO® were €25.4 million in the first half of 2021 compared to €28.4 million in the first half of 2020. While the COVID-19 pandemic is continuing to adversely impact the travel industry and vaccine sales to the private market, the impact on IXIARO® sales during the first half of 2021 was mitigated by the Company’s contract with the U.S. Government’s Department of Defense.

September 9, 2020 - Valneva SE announced the signing of a new contract, lasting up to 3-years, with the U.S. Department of Defense (DoD) to supply its Japanese encephalitis vaccine IXIARO®. This new contract has one base year, plus two option years, with a base-year value of $61 million. Deliveries for the base year will commence in the fourth quarter of 2020. The DoD has the option to purchase a total of $76 million – $105 million worth of IXIARO® across the 2 option years.

March 8, 2020 – Valneva SE announced that the Food and Drug Administration (FDA) had approved the extension of the shelf life of its Japanese encephalitis vaccine IXIARO from 24 months to 36 months.

January 14, 2020 – The U.S. Department of Defense (DoD) has exercised an option to purchase 80,000 additional doses of its Japanese encephalitis (JE) vaccine IXIARO®.

July 19, 2019 - Japanese Encephalitis Vaccine: Recommendations of the Advisory Committee on Immunization Practices.

June 5, 2019: The European Medicines Agency (EMA) has approved the extension of the shelf life of the Japanese encephalitis vaccine IXIARO from 24 months to 36 months.

March 1, 2019 – According to 2 unanimous votes by the Advisory Committee on Immunization Practices (ACIP) committee at its February 27, 2019 meeting, Japanese Encephalitis (JE) virus vaccination recommendations have been expanded. 

Japanese Encephalitis Virus Overview

JE is a mosquito-borne flavivirus, is the most common vaccine-preventable cause of encephalitis in Asia. JE occurs throughout most of Asia and parts of the western Pacific. For most travelers to Asia, the risk for JE is very low but varies based on travel duration, season, location, activities, and accommodations.

JE virus is maintained in an enzootic cycle between mosquitoes and amplifying vertebrate hosts, primarily pigs and wading birds. JE virus is transmitted to humans by infected mosquitoes. In most temperate areas of Asia, JE virus transmission is seasonal, and large outbreaks can occur. In the subtropics and tropics, transmission can occur year-round, often intensifying during the rainy season.

Ixiaro Vaccine Clinical Trials

Ixiaro Japanese Encephalitis vaccine has been involved in over 60 clinical trials.