When is the Japanese encephalitis vaccine needed?

Indonesia is one of many Asian countries where Japanese encephalitis (JE) infection is endemic. Transmission of Japanese encephalitis occurs through mosquito bites Culex tritaeniorhynchus who are infected with the virus. Japanese encephalitis can cause paralysis and death if treated too late. A proven preventative measure to reduce the spread of infection is the Japanese encephalitis (JE) vaccine.

What is japanese encephalitis (JE)?

Japanese encephalitis is a disease caused by mosquitoes Culex tritaeniorhynchus. The Indonesian Pediatric Association (IDAI) explains on its official website that this disease most often affects most Asian countries, such as Japan, China, Korea, Thailand, including Indonesia.

Mosquito Culex tritaeniorhynchus there are many in rice fields, irrigation areas, and pig farms. The risk of spreading Japanese encephalitis to humans usually increases during the rainy season and at night.

Most cases of Japanese encephalitis do not show specific symptoms. In some people, symptoms of this disease can appear 5-15 days after being bitten by a mosquito infected with the virus. Initial symptoms can include fever, chills, headache, weakness, nausea, and vomiting.

It is rare for sufferers of Japanese encephalitis infection to show severe symptoms. Even so, the symptoms of a severe infection can be characterized by:

Inflammation of the brain (encephalitis)
Accompanied by a sudden high fever
Headache
Nape stiff
Disorientation (dazed or confused)
Coma
Seizures
Paralysis.

In very severe cases, this disease can cause death. IDAI explains that for 67 thousand cases of JE each year, the death rate is up to 20-30 percent.

If you can survive, the possibility of causing neurological symptoms is 30-50 percent.

Japanese encephalitis is highest in children, especially those younger than 10 years.

Why is the Japanese encephalitis vaccine important?

Until now, no cure has been found to treat this disease, but it can be prevented by using a vaccine. The Japanese encephalitis (JE) vaccine program has been proven to be effective in preventing and reducing the transmission rate of this disease.

Several countries in Asia that carry out the japanese encephalitis immunization program are Japan, China, Korea, Taiwan, and Thailand. They run this program for children and have reduced the number of people with JE disease in the last few decades.

How about Indonesia? In 2016, the National Immunization Expert Advisory Committee introduced the japanese encephalitis vaccine into the national immunization program in areas with the most cases of JE in Indonesia.

The introduction of the JE vaccine was carried out in 2017 in Bali targeting children aged 9 months to 15 months.

How does the Japanese encephalitis (JE) vaccine work?

Just like vaccines for other infectious diseases, the Japanese encephalitis vaccine serves to protect you from disease before you are actually infected.

This vaccine is made from a killed Japanese encephalitis virus, which aims to trigger the body's immune system response by forming antibodies. These antibodies will fight the virus before it spreads and causes disease.

This vaccine needs to be given once after 12 months of age if you are in an endemic area or a tourist who will travel to an endemic area. Then it is repeated for long-term protection which is 1-2 years thereafter.

Who needs the Japanese encephalitis (JE) vaccine?

WHO recommends giving Japanese encephalitis immunization to tourists who will stay for more than 1 month in endemic areas (areas with the highest number of sufferers).

However, based on recommendations from the Indonesian Pediatric Association (IDAI), the Japanese encephalitis vaccine can be started for babies aged 12 months (1 year) to 16 years.

The immunization schedule for this disease is divided into two sessions with a distance of 28 days, as follows:

Adults aged 18-65 years can get the second vaccine as early as 7 days after the first vaccine
The second vaccine is given at least one week before traveling to endemic areas
Vaccine booster should be given if the child has received the previous two vaccines

For immunization of children aged three years and over and adults, the dose of JE Ixiaro vaccine is 0.5 ml. Meanwhile, for children aged 12 months to 2 years it is 0.25 ml for each vaccine.

JE vaccine for tourists

Japanese encephalitis has a low risk of transmission if travel is made during the non-transmission season of the JE virus. Increased risk of infection with this disease in tourists in endemic areas, namely:

Long travel time
Traveled during the transmission season of the JE virus
Visiting rural areas
Outdoor activities

To reduce the risk of transmitting the JE virus infection, tourists visiting endemic countries should consult a doctor for the vaccine.

The following are some groups of people who are recommended to do the Japanese encephalitis vaccine:

Tourists from abroad or from outside the city (non-endemic) who will stay for more than 1 month in these endemic areas.
Tourists who stay for less than 1 month and often visit areas where the virus develops.

Japanese encephalitis vaccine should be given within 10 days before departure.

However, if you and your family do not plan to travel to endemic areas, there is really no need for this vaccine. Pregnant women are also not advised to get this vaccine during pregnancy.

Are there any conditions that cause someone to delay the Japanese encephalitis (JE) vaccine?

The Ixivaro vaccine contains protamine sulfate, a chemical compound that causes allergic reactions in some people. Consult your doctor about allergies that you or your little one have so that medical personnel can handle the right treatment according to the condition.

The Center for Disease Control and Prevention (CDC) states that giving JE vaccine to pregnant women is postponed first because there is no research on whether it is safe or not.

Delaying vaccines to your little one is different from children who are not immunized, consult a doctor if your child has a problem with the ingredients in the vaccine.

What are the side effects after the japanese encephalitis (JE) vaccine?

Just like other types of drugs, the Japanese encephalitis vaccine has side effects that may occur, such as:

There is pain, redness, and swelling in the area where the vaccine was injected.
Fever, this is usually experienced by many children. However, in most cases, this is not a dangerous thing.
Headache and muscle pain, usually this happens in adults.

If your little one experiences the side effects of excessive immunization, then immediately consult a doctor to find out more.

Also, make sure you and your family members are not allergic to the Japanese encephalitis vaccine before getting it. However, the benefits of JE immunization outweigh the side effects, so it is important to give it to children and not to be late for immunization.

What should be considered after doing the JE vaccine?

The thing to remember is that the Japanese encephalitis (JE) vaccine only prevents transmission, it does not work 100 percent. You should still protect yourself from mosquito bites when you go or live in high-risk areas.

Some things you can do to avoid mosquitoes are:

Wearing long sleeves and trousers.
Spray the room with insecticide in the afternoon to kill any mosquitoes that enter during the day.
Use a mosquito repellent containing diethyltoluamide (DEET) or eucalyptus.

When using a cream or insect repellent, pay attention to the things below:

Avoid wearing on areas with cuts or irritated skin.
Do not wear near eyes and ears.
Avoid spraying mosquito repellent directly on your face, apply it in your hands first and then apply it to your face.
Apply mosquito repellent after applying sunscreen.

If the child has an allergic reaction to some mosquito repellent products, stop using them.

When to see a doctor

The JE vaccine can be taken at any time, unlike the MMR vaccine or hepatitis B vaccine which has a certain schedule.

However, you need to tell your doctor or other medical personnel if you have a fever, are pregnant, or are breastfeeding. Usually the doctor will advise to postpone the vaccine.

You should see a doctor if you have a very severe allergic reaction (anaphylaxis) to the ingredients and ingredients in the vaccine.