Vaccine Info

Jenvac Japanese Encephalitis Vaccine

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Last reviewed
February 24, 2024
Fact checked by
Robert Carlson, MD

JENVAC® Vaccine

JENVAC® is a single-dose inactivated Japanese Encephalitis (JE) Vaccine. This Vero cell-derived vaccine is prepared from an Indian strain (Kolar- 821564XY) of the JE virus. JENVAC has been developed in collaboration with India's National Institute of Virology. It is a safe and highly effective vaccine that protects against all known strains of Japanese Encephalitis.

JENVAC® is a safe and highly effective vaccine that protects against all the known strains of JE. World Health Organization showed that 6,383 cases of JE were reported in India between 2018 and 2022.

Bharat Biotech is a pioneering biotechnology company based in India known for its world-class R&D and manufacturing capabilities. 

JENVAC Indication

Japanese Encephalitis is the most common cause of viral Encephalitis in Asia. JE is a mosquito-borne flavivirus and belongs to the same genus as dengue, yellow fever, and West Nile viruses. JE is transmitted to humans through bites from infected mosquitoes of the Culex species. Most JE infections are mild (fever and headache) or without apparent symptoms, but approximately 1 in 250 infections result in severe clinical illness. Severe disease is characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, paralysis, and ultimately death.

JE's case-fatality rate can be as high as 30% among those with disease symptoms. Of those who survive, 20%–30% suffer permanent intellectual, behavioral, or neurological sequelae such as paralysis, recurrent seizures, or the inability to speak. There is no antiviral treatment for patients with JE. Treatment is supportive to relieve symptoms and stabilize the patient.


Data from a 2-dose study shows that a single dose of JENVAC is sufficient to elicit the immune response as the subjects who received a single dose were 98.67% sero-protected, and the 4-fold sero-conversion was at 93.14% for the ≥1 year to ≤50 years age group. JENVAC vaccine is administered intramuscularly into the deltoid region of the upper arm for adults and the anterolateral regarea of the thigh for children. As per the Recommended immunization schedule (2018-19), the JE vaccine should be administered at 12 months and 13 months. Infants younger than two months should not be administered JE the vaccine; People who have had a life-threatening allergic reaction to the JE vaccine or any ingredient in the vaccine.

JENVAC Adverse Events

The most common adverse events noted were pain, swelling, or redness where the shot was given, headache and muscle aches (mostly in adults), and low fever (mainly in children). Serious side effects from the JE vaccine are very infrequent.

JENVAC Vaccine News

February 2024 - India's government will vaccinate over 25 lakh children in four districts, including Indore, Bhopal, Narmadapuram, and Sagar, beginning February 27, 2024. 

August 1, 2022 - Japanese Encephalitis has claimed four more lives in Assam, India, taking the death toll to 52.

Clinical Trials

No clinical trials found