Japanese Encephalitis (JPE) (日本脳炎Nihon No-en )

As of April 1, 2016 JPE vaccination is now routine which will be given free of charge for children of certain ages in Hokkaido

Children born between April 2, 1995 and April 1, 2007 who did not receive the phase 1 and 2 vaccinations, due to a recommendation to withhold them in 2005 can receive the vaccinations up to the age of 20.
A list of medical institutions offering the vaccine is available by phone at the Sapporo City Call Center. Dial 011(222)4894.

What is Japanese Encephalitis?

It is a disease which is transmitted by JPE virus. JPE is not contagious from man to man. Mosquitoes carry JPE virus from infected swine to humans. Avoid mosquito bites especially during summer when they are most active. JPE is prevalent in south-east Asia, south Asia and northern Australia and there are around 40,000 patients every year.
Most JPE virus infections do not show any signs of the disease. One to four in a thousand show prominent symptoms. There are around 10 cases every summer in Japan.
Symptoms of JPE consist of ①high fever for several days, ②headache and vomiting followed by acute photosensitivity, ③disturbed consciousness and brain malfunctions. The disease leaves neurological disturbances in 50%, and may lead to death in 1/6.5 patients.

JPE Vaccination policy in Hokkaido

The vaccination for JPE has not been recommended in Hokkaido, because JPE virus is only transmitted by the specific kind of mosquitoes (Kogata-aka-ieka) that fly 8 kilometers and believed not to live in Hokkaido. For the residents of Hokkaido the JPE vaccine is now recommended. The chances for Hokkaido residents to get infected are higher then before. They travel often to Honshu and south-east Asia. The specific mosquitoes may breed in Hokkaido, in the near future due to global warming.
Some current surveys show high antibodies to JPE in 10 % of swine at some farms in southern part of Hokkaido. These pigs were once infected by the JPE virus.  The specific mosquitoes are rarely found in Hokkaido. The carrier mosquitoes are under investigation.

Immunization schedule for children

Primary immunization: starting from 6 months to 90 months after birth
Recommended schedule: Start from 3 years of age and receive 2 shots separated by 6-28 days. The third shot is required at least 6 months, preferably one year after the second shot. One more shot at 9-13 years of age is required to boost the effect of immunization.

Immunization for people 20 years of age and older (voluntary )

Three shots will establish primary immunization, and it is followed by a booster shot every 4-5 years. This is an inactivated vaccination which does not establish permanent immunization.

Details about JPE Vaccination offered by Sapporo city (in Japanese) :

Consent form for people aged between 13 years and 19 years :

Questionare for people over 13 years old :

Nobuko Kawamata MD