Japanese Encephalitis Vaccine

Japanese Encephalitis Vaccine

Last Updated: March 1, 2021
HealthLinkBC File Number: 41h
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Travel vaccines are recommended for people travelling to or working in some countries. It is important to talk to your health care provider or visit a travel clinic at least 6 to 8 weeks before you travel.

Most travel vaccines are not covered by the provincial medical services plan (MSP). You can check with your local travel clinic to find out the cost.

Bring a record of all vaccines you have received in the past to the travel clinic. It is important to keep a record of the travel vaccines you receive and to take this with you on your trip.

What is Japanese encephalitis vaccine?

Japanese encephalitis vaccine helps protect against the Japanese encephalitis virus, an infection spread by infected mosquitoes. The vaccine is approved by Health Canada.

Who should get the vaccine?

If you are travelling to or working in Eastern Asia, Southern Asia, or the Western Pacific for 1 month or more you may need to get the vaccine.

The risk of getting the virus depends on the season of travel, location, length of stay and types of activities you do. Generally, the risk of infection is greater in agricultural or farming areas. The travel clinic doctor or nurse will advise if you should receive the vaccine.

The vaccine is approved for adults and children age 2 months of age and older. It is given as a series of 2 doses, or shots, 7 or 28 days apart for adults. For children under 18, give 2 doses, or shots, 28 days apart. An extra dose of vaccine, called a booster, should be given 12 to 24 months later if you continue to travel or work in areas that has the virus. A second booster dose is not required for at least 10 years.

Who is most at risk?

Infants and elderly are most at risk of getting severely sick.

It is recommended not to travel with an infant or a young child to the high risk areas. If you cannot avoid travel, use protective measures to prevent mosquito bites. For more information on preventing mosquito bites, see HealthLinkBC File #41f Malaria Prevention.

If your child will be travelling for a long period of time, talk to your health care provider about the risks of Japanese encephalitis. Discuss the benefits of your child receiving an approved Japanese encephalitis vaccine in Canada before you leave. A long period of time is over 1 month during high risk season from July to October, or over 6 months during the rest of the year.

What are the benefits of the vaccine?

The Japanese encephalitis vaccine is the best way to protect against Japanese encephalitis virus, a serious and sometimes fatal infection. Because the vaccine does not provide complete protection, it is also important to prevent mosquito bites while you travel.

What are the possible reactions after the vaccine?

Vaccines are very safe. It is much safer to get the vaccine than to get Japanese encephalitis.

Common reactions to the vaccine may include soreness, swelling or redness where the shot was given. Fever, headache, rash, muscle pain and feeling unwell are also common. Rare reactions include mild encephalitis, dizziness and vomiting. These reactions can begin soon after getting the vaccine and may last for several days.

Acetaminophen (e.g. Tylenol®) or ibuprofen* (e.g. Advil®) can be given for fever or soreness. ASA (e.g. Aspirin®) should not be given to anyone under 18 years of age due to the risk of Reye Syndrome.
*Ibuprofen should not be given to children under 6 months of age without first speaking to your health care provider.

For more information on Reye Syndrome, see HealthLinkBC File #84 Reye Syndrome.

It is important to stay in the clinic for 15 minutes after getting any vaccine because there is an extremely rare possibility, less than 1 in a million, of a life-threatening allergic reaction called anaphylaxis. This may include hives, difficulty breathing, or swelling of the throat, tongue or lips. Should this reaction occur, your health care provider is prepared to treat it. Emergency treatment includes administration of epinephrine (adrenaline) and transfer by ambulance to the nearest emergency department. If symptoms develop after you leave the clinic, call 9-1-1 or the local emergency number.

It is important to always report serious or unexpected reactions to your health care provider.

What is Japanese encephalitis?

Japanese encephalitis is a serious and life-threatening infection caused by a virus. Symptoms appear 5 to 15 days after infection.

About 1 in 200 infected with the virus will develop encephalitis, which is an inflammation or swelling of the brain. More than half of those will die or have permanent brain damage. Infection during the first 6 months of pregnancy may result in infection of the baby and miscarriage. In its early stages, Japanese encephalitis is similar to a flu-like illness.

Symptoms may include headache, fever, nausea, vomiting, diarrhea, confusion and other changes in behavior. Currently, there is no drug treatment for the disease.

Japanese encephalitis virus spreads to people from bites from infected mosquitoes that live in Southern and Eastern Asia and the Western Pacific. The virus cannot be spread from person to person, or by mosquitoes in Canada.

Mature Minor Consent

It is recommended that parents or guardians and their children discuss consent for immunization. Children under the age of 19, who are able to understand the benefits and possible reactions for each vaccine and the risk of not getting immunized, can legally consent to or refuse immunizations. For more information on mature minor consent see HealthLinkBC File #119 The Infants Act, Mature Minor Consent and Immunization.

For More Information

For a list of travel clinics in B.C., visit the Public Health Agency of Canada: www.canada.ca/en/public-health/services/travel-health/yellow-fever/vaccination-centres-canada-british-columbia.html

For more information on travel vaccines, see HealthLinkBC File #41c Travel Immunizations for Adults.

For information on insect bite prevention, visit Government of Canada – Insect bite prevention: https://www.canada.ca/en/public-health/services/diseases/insect-bite-prevention.html