Tick-borne encephalitis (TBE) is a human viral infection that can affect the central nervous system (CNS). TBE is a disease with two distinct stages:

• The first stage of TBE is characterized by relatively mild influenza-like symptoms, and many people make a complete recovery after this stage of infection.
• Approximately one-third of those infected with TBE, however, will move to the second stage of the disease after a short remission period.
• The second stage of TBE is characterized by meningitis, encephalitis, or meningoencephalitis and associated symptoms, such as headache, vertigo, drowsiness, confusion, or even paralysis.
• These serious acute CNS infections may result in long-term neurologic sequelae that can affect 10-58% of patients, depending on the viral subtype, or can even be fatal.

Tick-borne encephalitis has an incubation period of 2-28 days. When the onset of symptoms is delayed, diagnosis can be challenging, as tick bites may not be reported. Up to 30% of infections require palliative treatment, and the case-fatality rate associated with clinical infection can vary from 0.5% to 20%, depending on the viral subtype.

Tick-borne encephalitis is caused by the TBE virus, which is a flavivirus

Tick-borne encephalitis is usually transmitted to humans through the bite of an infected tick (Figure 1) or, less commonly, by ingestion of unpasteurized milk from infected animals such as cows, sheep, or goats.

Figure 1. A tick

Eight species of tick that can transmit the TBE virus have been identified.

The virus is maintained in small mammals, domestic livestock, and some species of birds. Small mammals are the main reservoir and hosts of the virus. Ticks can become infected at any stage in their lifecycle by feeding on infected animals (Figure 2). The virus can also be passed between mating and co-feeding ticks. Humans become infected by being bitten by a tick or, very occasionally, by consuming unpasteurized milk from infected livestock.

Living or working in areas where TBE is endemic are the leading risk factors for TBE infection. The risk of TBE infection is also increased:

• if engaged in forestry, woodcutting, farming, or military activities
• if undertaking field work in forested TBE-endemic areas
• if taking holidays in TBE-endemic or TBE-epidemic areas
• during outdoor leisure activities, such as hiking,10 mushroom picking, camping, or hunting in TBE-endemic or
• TBE-epidemic areas.

Living or working in areas where TBE is endemic are the leading risk factors for TBE infection

There is no specific antiviral treatment or post-exposure vaccination available for TBE. Symptomatic therapy, which can significantly reduce morbidity and mortality, is available; however; treatment is only helpful in controlling symptoms. This means that prevention of infection is key to disease control.

Prevention of infection is key to disease control

Awareness of the risk of TBE infection is essential and the following precautions are recommended when in endemic areas between May and October: cover arms, legs and ankles; use insect repellent on socks and outer clothes; and remove any ticks attached to the skin. However, these precautions are not sufficient for long-term exposure in endemic regions.

Yes there is. Active vaccination against TBE is the most effective method to protect against the disease.

The World Health Organization (WHO) recommends vaccination for all those living in areas where TBE is endemic. In addition, vaccination is recommended for work or travel in warm, forested parts of endemic areas, particularly in spring and summer when ticks are most prevalent.

Vaccination is the most effective method to prevent TBE

Prophylactic TBE vaccines have been in use for more than 30 years. Those that have been used widely were first produced during the 1970s. These first TBE vaccines were developed using the TBE virus strain, Neudörfl, isolated in Austria.

In Europe, two TBE vaccines are currently available for both adults and children; the primary vaccination course using the conventional schedule requires three doses, followed by booster doses every 3-5 years. The immune response to TBE vaccines has been well documented, and there have been many years of post-marketing experience.

Over many years of development, several modifications have been made to the formulations of both vaccines. Encepur is a second-generation, formalin-inactivated TBE vaccine, with formulations for both adults and children.

Encepur is a second-generation, formalin-inactived TBE vaccine, with formulations for both adults and children.

Encepur Adults and Encepur Children are purified, inactivated whole TBE virus vaccines. The products are illustrated in Figure 2.

Figure 2. Encepur adults and Encepur children product packaging

Encepur uses an inactivated European TBE virus strain: K23. Both Encepur Adults and Encepur Children are free from preservatives, protein-derived stabilizers, and human serum albumin (HSA).

Encepur Adults is indicated for active vaccination against TBE in persons =12 years of age. Encepur Children is indicated for infants from 1 year of age to children <12 years of age. The vaccines are intended particularly for adults and children who are permanently, or temporarily, in areas where TBE is endemic.

In countries where Encepur Adults and Encepur Children have marketing authorizations, both are licensed based on a 3-dose schedule administered over a 12-month period. The recommended interval between the first and second dose is 1-3 months, and between the second and third dose 9-12 months. Booster doses should start 3 years after completion of the schedule and be repeated at intervals of 3-5 years.

A rapid schedule for vaccination can also be used if a fast immune response is needed. When using the rapid schedule, booster doses should start 18 months after completion of the schedule and be repeated at intervals of 3-5 years.

Tick-borne encephalitis is a central nervous system (CNS) infection, which can have serious long-term effects and can, in some cases, be fatal. TBE is transmitted to humans by ticks and is endemic to many parts of Europe and Asia.

There is no treatment for TBE; however, it is preventable through prophylactic vaccination.

Encepur is free from preservatives, protein-derived stabilizers, and HSA, reducing the risk of adverse events to this vaccine.

Encepur is well tolerated in both adults and children, and comparable to other TBE vaccines.

Encepur provides an excellent immune response for adults and children that is also broad and sustained.