The TBE vaccination

What is TBE?

Tick-borne encephalitis (TBE) is a viral disease transmitted by ticks and is endemic in large parts of Europe and Asia. Endemic means that this disease can occur permanently in a specific location or region.

In Germany, there is an increased risk of TBE infection in the following regions: Bavaria, Baden-Württemberg, southern Hesse, southeastern Thuringia, Saxony, and, since 2022, also in southeastern Brandenburg. There are also some smaller risk areas in central Hesse, Saarland, Rhineland-Palatinate, Lower Saxony, and North Rhine-Westphalia.

In 2023, 475 cases of TBE were reported. This is 16% fewer than in the previous year, 2022.

Symptoms, Course, and Treatment

The disease is usually asymptomatic or presents with mild symptoms similar to the flu. However, up to 30% of infected individuals experience a two-phase course: initially, patients appear to suffer from a common viral infection, from which they recover quickly. A few days later, a second phase of the illness develops, affecting the central nervous system in the form of meningitis (inflammation of the meninges), meningoencephalitis (inflammation of the brain and meninges), or meningomyelitis (inflammation of the meninges and spinal cord). Meningitis usually resolves without complications, while the other forms can lead to severe complications with long-term effects (spinal cord injuries, altered mental status, cranial nerve palsies) or even death.

A diagnosis of tick-borne encephalitis (TBE) is confirmed by detecting the virus in a blood sample using PCR. During the course of the illness, the body develops antibodies, which can also be detected.

Tick-borne encephalitis (TBE) is usually diagnosed without complications, but the other forms can lead to severe complications with long-term effects (spinal cord injuries, altered mental status, cranial nerve palsies) or even death. There is currently no causal therapy for the disease, meaning that no medications exist to combat the virus after an infection has occurred.

However, there is a vaccine against tick-borne encephalitis (TBE), which, in addition to exposure prophylaxis (i.e., wearing long clothing and checking the body for ticks in the evening), is recommended before traveling to endemic areas. The vaccination recommendation applies to all children and adults who live, work, or vacation in a TBE risk area.

The TBE vaccine is approved for children from the age of one.

Vaccination Schedule

To achieve full protection, three vaccinations are administered. The second vaccination takes place 2–12 weeks after the first, and the third vaccination 5–12 months later. Protection lasts for at least three years. According to a 2023 study, 97% of all fully vaccinated individuals achieve complete protection. There is also an accelerated vaccination schedule, for example, for short-notice travel to a high-risk area.

Studies show that even vaccination schedules deviating from these guidelines offer good protection. For example, a primary immunization series administered years ago can be boosted with a second dose to achieve almost complete protection. In practical terms, this means: Missing a vaccination appointment is not a problem. Simply get it done as soon as possible.

It is important to know that the vaccination can only provide lasting protection if it is administered before infection. It takes approximately 7–14 days for protective antibodies to develop, but truly reliable protection is only achieved after two doses. To ensure these are administered in time for the start of tick season in spring, the Standing Committee on Vaccination (STIKO) recommends beginning the vaccination series in winter.

Which vaccine?

Currently, there are two equally effective vaccines on the market (FSME-IMMUN® and ENCEPUR®). Studies show that switching between the two vaccines within a single vaccination series is even possible without any loss of efficacy. Nevertheless, the general recommendation is to stick with one vaccine. The vaccines are effective against all three known strains of the virus that can cause tick-borne encephalitis (TBE) worldwide (European, Siberian, and Far Eastern subtypes).

Vaccination after infection?

After a confirmed TBE infection, immunity lasts for several years. Since the exact duration of protection is not known, re-immunization with a dose of TBE vaccine is recommended if there is still a risk of exposure.

Side effects

Overall, the TBE vaccination has few side effects. Studies have observed the following general symptoms in the first 1–4 days after vaccination: elevated temperature, headache, fatigue, malaise, and gastrointestinal discomfort. Numbness or paresthesia occurred rarely. Temporary joint and muscle pain was more common. Symptoms were typically most pronounced after the primary immunization and less frequent with booster vaccinations. Pain and redness at the injection site occurred in up to 45% of cases, while fever was observed in only 5–6% of the adult subjects studied. However, approximately 15% of children under 3 years of age developed a fever after the first vaccination. Therefore, the assessment of eligibility for vaccination in this patient group should be particularly thorough and always conducted in consultation with the parents. No serious or life-threatening side effects were observed in any of the completed approval and observational studies.

Does the TBE vaccination also protect against Lyme disease?

In addition to the TBE virus, ticks can transmit other diseases, such as Lyme disease, a bacterial infection that is far more common than TBE. There is no vaccine against Lyme disease, but there is effective antibiotic treatment. The Lyme disease bacteria are only transmitted to humans after a prolonged feeding period of several hours and can occur throughout Germany. The TBE vaccination does not protect against Borrelia bacteria.

Conclusion:

In summary, the TBE vaccination is a safe, well-researched, and highly recommended vaccination if there is a relevant risk of TBE. This applies to all children from the age of one. Younger infants should be especially well protected in risk areas by clothing and shielding (for example, using a stroller and, if necessary, a mosquito net) to prevent ticks from reaching the baby's skin. After vaccination, the typical symptoms in children are comparable to those of other vaccinations: slightly elevated temperature, pain, redness at the injection site, and general discomfort. These symptoms subside quickly and should be accepted in exchange for the reliable immunity that the vaccination provides. Important: the TBE vaccination cannot be considered post-exposure prophylaxis. This means that after infection with the TBE virus, vaccination can no longer provide reliable protection.