Tick-borne encephalitis and TBE vaccine

The tick season is much longer than the summer months. Ticks are active and are looking for a suitable food source at temperatures above 5 degrees – from early spring to autumn. Ticks spread two dangerous pathogens: borrelia-bacteria and tick-borne encephalitis virus (TBEV). The number of TBE cases have increased in Finland during the last five years.

An effective vaccine against tick-borne encephalitis (TBE) is available, given as a series of three vaccines. Children between 1-15 years and adults have their own vaccines. The TBE vaccine is officially recommended in certain parts of Finland.

There is currently no vaccine for borreliosis i.e Lyme disease, that is caused by borrelia-bacteria. For this reason, tick check should be performed daily also in persons vaccinated against TBE. You can try to avoid the bites of ticks by wearing protective clothing and avoiding walking in the long grass. There are also repellents sprayed on skin or clothes against ticks.

Increasing number of TBE virus cases 

Approximately 70–80 TBE cases have been diagnosed in Finland each year. However on the year 2021 this number doubled to 160 cases. The TBE virus is mainly found in Åland, Turku archipelago and Helsinki metropolitan area. However, there are an increasing number of observations from other parts of Finland as well. It is currently quite difficult to name a completely ‘tick-safe’ area.

There is a lot of TBE virus just behind the eastern border and in all the Baltic countries. There are also significant numbers of diseases in Central Europe, especially in Germany, Austria, Slovenia, Hungary, the Czech Republic and Croatia. Global warming is expected to change the spread of the disease. In Lithuania, for example, the number of cases has increased 15-times in the last 30 years.

TBE is a dangerous disease

Tick-borne encephalitis, or TBE, is generally more dangerous for the older people. An estimated one-third of infected patients develop a disease of the central nervous system. In adults in particular, the disease can spread to the brain tissue, resulting in paralysis and permanent damage.

Meningitis is a more common form of the disease in young children. Permanent central nervous system damage in children as a result of TBE is less common. However, even small children can get a severe form of the disease as a result of the infection. Studies have also shown that children have long-term learning and memory problems and behavioral disorders, even after a mild form of the disease.

TBE vaccine schedule

The basic immunisation for adults and children includes 3 injections. The first one is ideally given during the winter/spring months and the second dose is given 1-3 months after the first. The third dose is given 5 to 12 months after the second dose. The first vaccine does not yet provide good protection, so it is important to complete the vaccination programme.

After the basic immunity provided by the three doses, the first booster is given three years after the third dose.

Following boosters are given according to age:

• For those under the age of 50, the next booster after 10 years
• At the age of 50-60, the booster is given every 5 years
• A person over the age of 60 booster is given every 3  years

All individuals who have a weakened immune system due to treatment or illness are given a booster every 3 years.

Vaccines have been well-tolerated. Local reactions (redness, pain at the injection site) have been reported to the same extent as with other intramuscular vaccines. The most common side effect is short-term headache after vaccination. The incidence of side effects decreases after the first vaccination.