Japanese encephalitis vaccination

Martina Feichter studied biology with an elective subject pharmacy in Innsbruck and also immersed herself in the world of medicinal plants. From there it was not far to other medical topics that still captivate her to this day. She trained as a journalist at the Axel Springer Academy in Hamburg and has been working for since 2007 - first as an editor and since 2012 as a freelance writer.

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The vaccination against Japanese encephalitis protects against infection with viruses that can cause encephalitis, which can sometimes be dangerous. The disease is particularly common in Asia and is transmitted by certain mosquitoes. Find out here how the Japanese encephalitis vaccination works, when it is recommended and what side effects it can have!

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. A83G04

This is what happens with the Japanese encephalitis vaccination

The vaccine against Japanese encephalitis is a so-called dead vaccine: It contains inactivated pathogens from the Japanese encephalitis strain SA14-14-2. It has been approved in Germany since March 31, 2009.

The inactivated viruses cannot make you sick, but they can still stimulate the body to produce specific antibodies. If a "real" infection with the Japanese encephalitis virus occurs later, the body is prepared - it can fight the pathogen quickly and in a targeted manner.

When does vaccination make sense?

Japanese encephalitis is the most common viral encephalitis in Asia. It is usually transmitted by mosquitoes in the vicinity of farms. So far there is no specific therapy against the often fatal disease. About a third of the survivors retain neurological sequelae (paralysis, delusions).

The risk of infection and illness seems to be very low for tourists. The authorities counted 55 severe cases of Japanese encephalitis among long-distance travelers between 1973 and 2008. Most stayed in a risk area for over a month.

Experts therefore recommend the Japanese encephalitis vaccination mainly in the following cases:

• For long-term stays in an endemic area of ​​the disease (South, Southeast and East Asia), e.g. as part of family visits or long-term trips
• For repeated short trips to an endemic area
• When traveling with an increased risk of infection for Japanese encephalitis (e.g. when staying overnight in rural regions of the endemic areas) - especially in the main transmission time (i.e. in the rainy season and after) and regardless of the duration of the trip

In addition, anyone planning a trip to an endemic area during the main transmission period should speak to a doctor beforehand about the possibility of a Japanese encephalitis vaccination. In individual cases, the vaccination can also be useful in cases other than those mentioned above. This is especially true for people who are at increased risk of developing Japanese encephalitis. Such an increased risk exists, for example:

• Children as well as adults who are 50 years of age or older
• Wearing a cochlear implant (general: if the blood-brain barrier is disrupted)
• High blood pressure (hypertension)
• Diabetes (diabetes mellitus)
• immunodeficiency
• Chronic kidney disease
• Increased exposure to the open air in the endemic area

In addition, the Japanese encephalitis vaccination can be useful for people who have professional contact with the pathogen (e.g. employees in medical laboratories). If a long-distance traveler wishes comprehensive protection, doctors usually also carry out a Japanese encephalitis vaccination - provided there are no contraindications (acute infection, allergy).

This is how the Japanese encephalitis vaccine is administered

A vaccine is currently available in Germany to prevent Japanese encephalitis. It can be given to children from two months of age, adolescents and adults. Children up to the age of three receive only half the usual vaccination dose.

Regardless of age, two vaccine doses are required for the primary vaccination:

• In the "normal" (conventional) vaccination schedule, these two syringes are administered 28 days apart.
• With the rapid vaccination schedule, the second dose is given seven days after the first. As shown by follow-up observations over 12 months, the body produces as many antibodies against the Japanese encephalitis virus as with the normal vaccination schedule. The rapid vaccination schedule is only possible for adults between 18 and 65 years of age.

Regardless of whether a normal or a fast vaccination schedule: The second vaccination dose should be given at least one week before possible contact with the Japan encephalitis virus. The body needs some time to produce antibodies.

How long does the vaccination last?

It is not known exactly how long the effects of the Japanese encephalitis vaccination will last. However, experts recommend a booster vaccination within 12 to 24 months after the second vaccination dose of the basic vaccination course if there is still or renewed possibility of infection. According to experts, the duration of the subsequent vaccination protection is around ten years, with no further data being available. It is best to ask your doctor whether and when it makes sense to have a booster vaccination in your case.

Japanese encephalitis vaccination: side effects

In adults, the most common side effects of the Japanese Encephalitis Vaccine are headache, muscle pain, tiredness, and pain and tenderness at the injection site. This can also become red, itchy, and swell slightly.

Children most often react to the vaccination with fever, diarrhea, flu-like symptoms, irritability and pain, redness and tenderness at the injection site.

Further recommendations for the Japanese encephalitis vaccination

The Japanese encephalitis vaccination is not recommended if someone has a known allergy to any of the ingredients or to the impurities in the vaccine's production process (such as protamine sulfate, formaldehyde).

Anyone who is hypersensitive or allergic to the first dose should not receive the second dose.

If you have an acute, serious infection with a fever, vaccination against Japanese encephalitis should be postponed.

There are insufficient data on the use of the Japanese encephalitis vaccine in pregnant and breastfeeding women. Vaccination during pregnancy and breastfeeding should therefore be avoided.

Where can I get vaccinated?

Before long trips such as to Asia, it is best to seek advice from a travel doctor. He or she can educate you about the risk of Japanese encephalitis (and other health hazards) at your travel destination and, if necessary, give you useful vaccinations such as the Japanese encephalitis vaccination.

He will also inform you about other protective measures that you should take to heart for the sake of your health during your trip. In the case of Japanese encephalitis, this primarily includes measures to prevent mosquito bites - the viral pathogens of the disease are transmitted by certain mosquitoes.

Japanese encephalitis vaccination: cost

Some health insurance companies reimburse their members for the Japanese encephalitis vaccination before going abroad. It is best to ask your health insurance company in advance.

Sometimes the Japanese encephalitis vaccine is given for professional reasons, for example because someone has to travel to Asia because of their job or because they work in a medical laboratory handling the Japanese encephalitis virus. In such cases, the employer usually pays for the Japanese encephalitis vaccination.

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