Japanese encephalitis vaccine#

Information about the Japanese encephalitis vaccine, who should consider it, how it is given, and how TeleTest fits into your pre-travel planning.

Japanese encephalitis is a mosquito-borne brain infection that occurs mainly in rural parts of Asia and the Western Pacific. The illness is rare in travellers, but it can be serious when it does occur, so the vaccine is recommended for travellers with specific kinds of exposure.

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What it is and why it matters#

Japanese encephalitis is caused by a virus in the same family as dengue, West Nile, and yellow fever. It is spread by the bite of an infected mosquito - usually a type of mosquito that feeds at dusk and into the night in rural areas, around rice fields and where pigs or wading birds are kept.

Most people who are infected have no symptoms or only a mild flu-like illness. In about 1 in 250 people who are infected, the virus reaches the brain and can cause severe inflammation (encephalitis), which can lead to permanent neurological damage or death.

The vaccine helps the immune system recognize and clear the virus before it can cause severe illness. It is given as a two-dose series, ideally completed at least one week before potential exposure.

Who should consider it#

The risk to most travellers is very low. The Public Health Agency of Canada and the Canadian Immunization Guide suggest the vaccine for:

  • Travellers spending one month or more in rural areas of countries where the virus is active (much of South Asia, Southeast Asia, parts of East Asia, and the Western Pacific), especially during the local rainy season or peak transmission months
  • Shorter-term travellers (less than one month) who plan extensive outdoor activity in rural areas - for example, camping, trekking, biking, working with animals, or staying overnight near rice fields
  • Travellers visiting areas with an active outbreak
  • Laboratory workers who handle the virus and people with specific occupational exposure

It is generally not needed for short trips limited to major urban areas.

How TeleTest helps#

  • What we do. We provide a pre-travel consultation, review your itinerary, talk through your individual risk, and (if appropriate) write the prescription for the Japanese encephalitis vaccine series. We also cover mosquito-bite prevention, which is essential even if you receive the vaccine.
  • What we do not do. We do not administer injectable vaccines on site. After we issue the prescription, you book your shots at a travel-medicine clinic, a public health unit, or (in some provinces) a pharmacy authorized to administer travel vaccines. We are also not a substitute for a comprehensive in-person travel-medicine visit if you are heading somewhere with multiple high-risk exposures.

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Common questions#

How is the vaccine given?#

It is given as two injections in the upper arm, with the second dose 28 days after the first. The second dose should ideally be at least one week before your departure date, so the full series should be planned about five weeks ahead.

Is there an accelerated schedule?#

For adults aged 18-65, an accelerated two-dose schedule (with the second dose 7 days after the first) may be considered when there isn't enough time for the standard schedule. This produces good short-term protection. For people outside this age range, only the standard schedule should be used.

How long does protection last?#

Protection from the primary series is high in the year after vaccination. A booster dose is recommended if you continue to be at risk one year or more after the primary series.

What are the side effects?#

Common side effects are mild: soreness, redness, or swelling at the injection site, headache, muscle aches, tiredness, or a low-grade fever. These usually go away in 1-3 days. Serious allergic reactions (anaphylaxis) are very rare.

Is the vaccine safe in pregnancy?#

There is limited data on use during pregnancy. The vaccine is generally avoided in pregnancy unless travel to a high-risk area cannot be deferred and the risk of infection outweighs the unknowns. The decision is individual - discuss it during your consultation.

Is the vaccine safe while breastfeeding?#

There is limited data, and the vaccine is not known to be harmful to a breastfeeding infant. As with pregnancy, the decision is individualized based on travel risk.

Can immunocompromised travellers receive it?#

Yes. It is not a live vaccine, so it can be given to people with weakened immune systems. The immune response may be reduced, so mosquito-bite prevention becomes even more important.

Do I still need mosquito-bite prevention if I'm vaccinated?#

Yes - always. The vaccine is highly protective but not 100%, and the same mosquitoes can also carry other diseases (dengue, chikungunya, malaria in some regions). Use a registered insect repellent (DEET or icaridin), cover skin at dusk and dawn, sleep under a treated bed net if needed, and choose accommodation with screens or air-conditioning.

Can I get it together with other travel vaccines?#

Yes. It can be given at the same visit as most other travel vaccines. Coordinate with the clinic or pharmacy administering your shots.

What if I don't have time to finish the series before I leave?#

A single dose offers only partial, short-lived protection. If you can, complete the second dose before you leave - even on the accelerated schedule. If that is not possible, focus heavily on mosquito-bite prevention and discuss with your clinician whether to start the series anyway so you have some protection.

How do I know if my destination is high-risk?#

Risk varies by country, region within a country, season, and the type of travel you are doing. Your TeleTest clinician will review your destinations, the time of year, the kind of accommodation and activities you have planned, and how long you will be there.

Cost and coverage#

The vaccine is not covered by provincial health plans. Out-of-pocket cost is typically in the range of about $200-$300 per dose at a travel-medicine clinic (so $400-$600 for the two-dose series), plus the administration fee charged by the clinic or pharmacy. Pricing varies, so it is worth phoning a few options near you.

Some workplace and private health plans cover travel vaccines in part or in full. Many travel-insurance and credit-card travel benefits also include partial reimbursement. Keep your receipts.

TeleTest charges a consultation fee for the travel review. A receipt is available for reimbursement.

Request a TeleTest travel consultation#

Last reviewed: Spring 2026. Reviewed by Dr. Mohan Pandit, Chief Medical Officer at TeleTest. We review this page periodically as medical guidelines, lab practices, and provincial programs evolve. This page is for general information, not personal medical advice. If you've noticed information that may be out of date or have suggestions, please contact us - we appreciate the help keeping these resources accurate.

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