Department of Health introduces vaccine against Japanese encephalitis

March 19, 2019

THE Department of Health introduced the Japanese encephalitis (JE) vaccine in regions mostly affected by the Japanese encephalitis disease.

The JE vaccine is the only effective measure to stop the transmission of JE and bring down the number of cases.

JE is a mosquito-borne viral disease and is the leading cause of viral encephalitis (inflammation of the brain) in Asia. Children are most at risk of JE. One in every 250 of those infected with the JE virus will succumb to severe illness, with an onset characterized by flu-like symptoms (sudden onset of high fever, chills, headache, and tiredness).

Disease may rapidly progress to severe encephalitis (infection of the brain). At this stage, a patient may experience symptoms like mental disturbances and progressive decline in consciousness to coma. Convulsions occur in 75% of pediatric patients.

Three out of 10 JE cases that progress to severe illness will die. Among those who survive, more than half will show serious residual neurologic, psychosocial, intellectual and/or physical disabilities such as paralysis, recurrent seizures, or inability to speak.

The JE virus is transmitted by Culex mosquitoes that breed in water pools and flooded rice fields. Those who live close to rice fields and pig farms are at most risk.

The Philippines is endemic for JE, with cases recorded in every region in the country. The DoH Epidemiology Bureau data showed that JE virus is the cause of encephalitis in 15% of all cases of acute encephalitis and recorded 122 laboratory confirmed JE cases in 2016 and 275 in 2017. In 2018, there were 340 laboratory confirmed JE cases, with Region III reporting the highest number of cases (110), followed by Regions I and II.

“Among the 12 countries with established JE transmission, only two countries have not introduced the vaccine in their immunization program, and one of these is the Philippines. Now, the Japanese encephalitis vaccine is available in the Philippines. This vaccine is WHO-prequalified and Philippine FDA approved. It is safe and effective. It has been used for over 30 years in 12 countries and given to more than 400 million children with an excellent safety record,” Health Secretary Francisco T. Duque III said.

The JE vaccine will be introduced this month in Regions I, II, III, and the Cordillera Administrative Region CAR. Children nine months old to less than five years old will be eligible to receive the vaccine through an immunization campaign.