Tick-Borne Encephalitis – Who needs to get vaccinated? Should I get vaccinated?
I’ve been wanting to write about the vaccine for tick-borne encephalitis (or TBE in short) for a while now, since the topic has become more and more popular in recent years for different reasons.
From an unknown infection and an esoteric and expensive vaccine, whom almost nobody used to receive, the TBE vaccine has turned into a popular topic among families taking casual trips with their children, especially to the Black Forest area (see the image).
So, there is this real infection out there, with a certain prevalence in the world, and it has a vaccine that is mostly administered at travel clinics. But the real question remains: who really needs this vaccine? Do all members of a family just passing near the Black Forest need to consider taking it? Or is it only meant for families who intend on picking mushrooms and camping in the forest for an extended period of time?
Let’s dive right into it and try to answer all your questions.
What is TBE?
TBE stands for Tick-borne encephalitis. Or in other words, an encephalitis (a brain infection) that is transmitted by the Ixodes tick.
This is actually a viral infection, and the virus, which belongs to the flavivirus family, spreads mostly through ticks or unpasteurized milk products.
Catching the virus usually results in an asymptomatic infection (approximately 75% of the cases are asymptomatic, but this depends on where the person gets infected). The other end of the spectrum is a very severe infection that can involve the brain.
If a person gets exposed in Europe, about 7-14 days following exposure they can develop non-specific signs and symptoms such as fever, muscle pain and headaches that last for 2-7 days. After somewhat of an improvement, 5-30% of people will develop a cerebellar infection, and will suffer vomiting and symptoms of meningeal irritation, including altered mental state and neurological complications. Elderly people are at risk of more severe disease.
Is there an available treatment for Tick-borne encephalitis?
The only treatment available is symptomatic treatment. There is no specific treatment against the virus.
It is possible, however, to prevent the disease from occurring, by proper behaviour and the use of a vaccine. Read more about this below.
Which areas are considered endemic?
The illness is spread in most countries in Europe. I wanted to jot down the countries that don’t have it (such as Portugal, Belgium, Holland and Luxemburg), but the problem is that this list changes every few years.
The disease is also found in some countries in the far east.
Nonetheless, the prevalence is higher in Austria, Poland, Hungary, Sweden, Slovenia, Czech Republic, Slovakia and Russia. That is why some of these countries vaccinate children for TBE as part of the scheduled routine vaccines at the age of 1.
Who is at risk of getting TBE?
In certain areas, antibodies against TBE can be found in up to 50% of the local population who lives on farms or works in forests. This means that about 50% of the locals who are prone to infection are people that have already been exposed.
As for travellers, it depends on where they are travelling, how long they are travelling for and the season they are travelling at.
Most of the reported cases have occurred in adults (aged 45-64 years), but obviously children are at risk as well.
When (which season) do most TBE cases occur at?
Most of the cases that have been reported in Europe occurred in summer, between April to November. July and August have had the most cases in previous years.
How can TBE be prevented?
This can be done firstly through adopting behaviours to avoid tick bites:
# Wear long sleeves and pants. A good trick is to tuck your pants into your socks and your shirt into your pants.
# Use insect repellant. Apply it not only on your skin but also on your clothes and gear. Some countries offer insect repellant that is more effective for the organisms found in that area.
# Avoid walking in bushy areas with high grass as much as you can
# After hiking in a forest, check your body for any ticks. If you find one, you must remove it in one piece and then disinfect that area of your skin. Keep in mind that the virus can spread into the human body after a very short exposure.
# Consider taking the vaccine prior to travelling
How should a tick be removed?
If you grasp the tick with a pair of regular tweezers and press too hard, you may crush the tick and by doing so squeeze all of its contents into your skin, including the virus responsible for TBE. Not such a good idea.
Try to use fine-tipped tweezers (certain areas in Europe sell tweezers that are made especially for tick removal), grasp the tick as close to the surface of the skin as possible and pull it upwards and away from the skin.
Once the tick is removed, disinfect the area of the skin where it was attached.
Who is the TBE vaccine meant for?
The Advisory Committee on Immunization Practices recommends the vaccine for people travelling or moving to a TBE-endemic area who will have extensive tick exposure based on planned outdoor activities and also to people who are travelling or moving and might engage in outdoor activities in areas where ticks are likely to be found.
What do the outdoor activities mentioned above include?
These include activities such as forestry, hiking, hunting, fishing, camping, cycling and collecting mushrooms, berries or flowers.
Why is it so difficult to define target populations for the vaccine?
The definition of target vaccine population remains vague when it comes to TBE as it is difficult to determine the length of exposure that poses one at risk and who really needs the vaccine. If a family is travelling to the Black Forest area for a week and is not planning on spending an extended period of time on site, one can argue whether or not they really need the vaccine.
On the other hand, young travellers who plan on spending a month camping around the forests of Austria obviously need to get vaccinated before their trip.
The problem is that most travellers’ plans are borderline, and it is difficult to tell whether they need the vaccine. The CDC has produced this flow-chart here but it is not very helpful.
Okay, you get my point. Let’s try to move on.
What is the name of the vaccine available for TBE?
The name of the vaccine is TICOVAC and it was manufactured by Pfizer.
TICOVAC Junior is indicated for children under the age of 16 (up until their 16th birthday). The appropriate dose for children under 16 is 0.25ml per dose.
TICOVAC (adults) – the dose for adults aged 16 and over is 0.5ml.
What type of vaccine is it and how is it administered?
This is an inactive vaccine (it is not live attenuated).
It is administered intramuscularly.
How many doses of the vaccine does one need to become immune?
A series of doses are required. The first two doses need to be given at least 3 months apart while the third dose is to be given between 5 months to 1 year after the second.
If more than a year has passed since the second dose, there is no need to repeat the first 2 doses and the third dose can be given right away.
Note that 2 doses of the vaccine provide you with sufficient immunity. That means that even if you are unable to receive the third dose of the vaccine prior to exposure, the first 2 will be sufficient for the upcoming season. As long as it has been at least 2 weeks since the second dose, you should be good to go.
What if we are travelling to a TBE-endemic area next month?
It is possible to get an “expedited” version of the vaccine schedule. That means you are able to receive your second dose two weeks after the first dose and then a third dose 5 months to 1 year after the second.
Keep in mind that even in the expedited version, you must wait at least 1 week (and some sources suggest 2 weeks) before exposure.
Practically speaking, this means that you need to visit the travel clinic at least 1 month before your intended travel plans.
How long does the vaccine provide immunity for? Is a booster necessary?
The immunity provided by 3 doses of the vaccine lasts about 3-5 years, depending on your age.
People between the age of 1 to 59 years need to receive a booster dose 5 years after the first dose of vaccine.
For elders over the age of 60, a booster dose is required 3 years after the first dose.
What are the possible side effects of the vaccine?
Common side effects are local side effects such as local tenderness. Other side effects that have been reported include fever, fatigue, headaches, and muscle aches.
Is there anyone who cannot get the vaccine?
People who can’t get the vaccine include infants under the age of 1 or anyone who has ever had a severe allergic reaction (also known as anaphylaxis reaction) to one of the components of the vaccine.
What about pregnant women?
Unfortunately, we do not have any medical information about the safety of this vaccine in pregnant women, so it is best to weigh out the benefits and risks and make an individualized decision.
Are there any other travel recommendations I should be aware of?
There certainly are! Read my post about Travelling Abroad with Children.
In summary, this is a very important topic. However, because the areas of TBE exposure and populations at risk are not very clear, I feel like this topic is often overlooked.
Sometimes, families that do not really need the vaccine receive it and vice versa.
As you’ve seen, it is also difficult for me to come up with clear cut recommendations for you, especially when it comes to families travelling to touristic, urban areas.
It is important to consider each case separately, depending on who the traveller is and their destination, preferably with a specialist working at the travel clinic.
Sorry guys. Good luck and enjoy your trip!
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