Japanese Encephalitis

What is Japanese Encephalitis (JE) ?

Japanese encephalitis (JE) is a viral infection which is spread by bites of an infected mosquito. It does not spread from person to person.

Generally, most infected people do not have any illness. About 1 in 200 infected persons may develop symptoms, which may include fever, headache, fits and loss of consciousness (caused by swelling of the brain).

Almost 25% of people with brain involvement may die and about half are left with residual neurological deficits.

Which are the vaccines are available against Japanese encephalitis and what is their schedule?

3 vaccines are available in India:

1) SA 14-14-2 vaccine: This is made from live, weakened virus. This vaccine is available only in the national immunization schedule of the Government of India. It is administered in a 2-dose schedule at 9 months and 16-24 months, to children 9 months of age onwards.

2) JEEV : This is made from the dead virus. It is administered in a 2-dose schedule to children 1 year of age onwards. The second dose is given at least 4 weeks after the first dose.

3) JENVAC : This is made from the dead virus. It is administered in a 2-dose schedule to children 1 year of age onwards. The second dose is given at least 4 weeks after the first dose. At present, there is no recommendation for booster doses.

Who should receive the JE vaccine?

· All children above the age of 9 months, residing in districts declared as endemic, by the Govt of India. In certain hyperendemic districts, the vaccine is also being given to adults. The vaccine is recommended for all the children residing in both, rural and urban areas in the endemic districts.

· This vaccine may be offered to travelers to endemic areas, during the transmission season (monsoon) and for travelers intending to stay for long periods, in endemic areas.

· It is also recommended for short term (less than a month) travelers, who will visit rural areas and have an increased risk for mosquito bites, or are not sure of their travel plans.

How safe are the JE vaccines?

The vaccines are safe. Common reactions include pain, tenderness, redness, or swelling at the site of the vaccination. Fever, headache, muscle aches, flu-like illness can occur.

Who should not receive the vaccine?

The vaccines should not be given to children who have had an allergic reaction after a previous dose of JE vaccine, or has any known, severe, life-threatening allergies to any vaccine component.