Japanese encephalitis vaccine: who it is for and when to start
Enter your age and the weeks left before departure: the checker says whether the two doses still fit and what the series costs at public price lists.
Japanese encephalitis: when to start
14 days before
latest start for protection on departure day
| Doses | 2 doses: day 0, day 7 |
| Protection | 7 days after the last dose |
| Published price per dose | $375 median, $325 to $420 (9 departments) |
| Series, median total with fees | $820 ($650 to $880) |
Schedule from the CDC Yellow Book (2026-02-20). Booster: Third dose ≥1 year after the series if exposure continues. Not medical advice.
| Health department | Per dose | Series with fees |
|---|---|---|
| Southwest Utah Public Health Department, UT | $325 | $650 |
| Florida Department of Health in Miami-Dade County (approximate prices, 2025 list), FL | $348 | $695 |
| Denver Health Public Health Institute, CO | $360 | $860 |
| Florida Department of Health in Lee County, FL | $369 | $782 |
| County of Orange Health Care Agency, CA | $375 | $820 |
| Fairfax County Health Department, VA | $375 | $840 |
| Aspetuck Health District, CT | $391 | $782 |
| Norwalk Health Department, CT | $400 | $880 |
| Tarrant County Public Health, TX | $420 | $840 |
Compiled by Radif Partners · Method and sources · CDC pages read October 24, 2026
Japanese encephalitis is a mosquito-borne virus of rural Asia and the western Pacific. It is rare in travelers, fewer than one case per million according to CDC's Yellow Book, but serious: about 20 to 30 percent of people who develop encephalitis die, and 30 to 50 percent of survivors keep lasting neurologic or psychiatric effects. CDC lists the vaccine for some travelers to 24 destinations, never for most. It is recommended for people moving to an affected area, staying a month or more or traveling there often, and to be considered for shorter trips with rural visits, hiking, camping or nights without screens or bed nets. The only US vaccine, Ixiaro, takes two doses: 7 to 28 days apart for adults of 18 to 65, 28 days apart at other ages, finished at least a week before travel. That means starting 14 days ahead at the earliest for an adult, 35 days outside that age range. A dose costs a median of $375 at the 9 health departments that publish a price.
Where the risk is
The virus lives in birds and pigs and passes to people through Culex mosquitoes that breed in flooded fields, which is why the risk follows rice cultivation and irrigation, not cities. CDC lists it for some travelers to 24 destinations: India, Nepal, Bangladesh and Sri Lanka in South Asia; Thailand, Vietnam, Cambodia, Laos, Burma, Malaysia, Indonesia and the Philippines in Southeast Asia; China, Japan, Taiwan and both Koreas; Papua New Guinea, Russia, and in Australia the Murray River area and the outer Torres Strait Islands. In temperate Asia cases peak in summer and fall; in the tropics transmission follows the monsoon and irrigation and can run all year. The Yellow Book gives Thailand's peak as May to October and the Philippines' as April to August, and asks clinicians to read those seasons with caution.
Is Japanese encephalitis on the list for your trip?
Travel vaccines CDC lists for most or some travelers on this trip
5 vaccines
| Yellow fever | Not needed on this route (Vietnam) |
| Malaria | Prescription tablets for areas of Vietnam |
| Longest lead time | 28 days before departure (Hepatitis B, 2 doses (Heplisav-B)) |
| Published price, these vaccines | $1,405 median, $1,215 to $1,550 |
Who CDC lists it for
The wording is the same on every country page. Recommended for travelers who are moving to an area with Japanese encephalitis to live, who spend long periods there, such as a month or more, or who travel there frequently. To be considered for travelers spending less than a month in such areas but doing activities that raise the risk: visiting rural areas, hiking or camping, staying in places without air conditioning, screens or bed nets; and for travelers who are not sure of their activities or how long they will stay. Not recommended for short-term travel limited to urban areas. Two weeks in Bangkok, Hanoi and Ho Chi Minh City falls in the last group; a month cycling through the Mekong delta in the rainy season falls in the first. Most trips sit in between, which is where the conversation with a clinician matters.
The schedule, and why the deadline comes early
Ixiaro is an inactivated vaccine approved from 2 months of age. Adults of 18 to 65 receive two doses 7 to 28 days apart; children, teens and adults over 65 receive them 28 days apart, and young children receive a half dose. The series must be complete at least one week before travel. For an adult the shortest plan is therefore a first dose 14 days before departure, the second seven days later, and a week of margin; for a traveler over 65 it is 35 days. A traveler who has only time for one dose should know that the label is a two dose series. A third dose one year or more after the series is advised only for people whose exposure continues.
Do the two doses still fit before departure?
Japanese encephalitis: when to start
14 days before
| Doses | 2 doses: day 0, day 7 |
| Protection | 7 days after the last dose |
| Published price per dose | $375 median, $325 to $420 (9 departments) |
| Series, median total with fees | $820 ($650 to $880) |
Side effects and who should talk it over
About a third of adults have pain or tenderness at the injection site; headache and muscle aches are the most common general reactions, and fever is the most common one in young children. Serious reactions are rare. The vaccine is not given after a severe allergic reaction to a previous dose or to one of its components, which include protamine sulfate. Pregnancy is a precaution: the vaccine has not been studied in pregnant women, so CDC advises deferring it unless the risk of infection on the trip outweighs the theoretical risk of the vaccine.
What it costs
Japanese encephalitis is usually the most expensive line of a travel vaccine list, because two doses are needed and each is priced like a specialty product. At the 9 health departments read for this site, one dose costs $325 to $420, and the series comes to $650 to $880 with their visit and administration fees. Ixiaro is not on the CDC private-sector price list, and travel-only vaccines are often outside insurance coverage, so a check with the plan comes first. The trip cost page adds it to the other vaccines of an itinerary, and the Thailand page shows how it combines with hepatitis A and typhoid.
Bites, the first protection
The mosquitoes that carry the virus bite mostly from dusk to dawn. Repellent on exposed skin, long sleeves in the evening, a screened or air-conditioned room and a bed net in rural lodging reduce the risk for every traveler, vaccinated or not, and they also protect against dengue and malaria in the same regions.