Tick-borne encephalitis is transmitted by the bite of infected ticks or rarely by drinking unpasteurised milk from infected goats, sheep or cows. Infected ticks are found in open country – forests, grassland, meadows and shrubbery, for example – where they are brushed onto clothing as people walk past. Ticks are usually the most prevalent during the spring and summer.
Using insect bite avoidance measures can reduce the risk of transmission of tick-borne encephalitis:
- Keep limbs covered – wear long-sleeved tops and trousers that can be tucked into socks for added protection. Clothing can be sprayed with a suitable insecticide such as permethrin.
- Insect repellents should be applied to exposed skin.
- After walking in risk areas the body should be checked visibly for ticks. If a tick is found, it should be removed as soon as possible by gripping it as close to the skin as possible, preferably using a pair of tweezers, and pulling away slowly. Take care not to squeeze the tick.
- Travellers should avoid drinking or eating unpasteurised dairy products in risk areas.
Anyone who has been bitten by a tick and who subsequently develops a flu-like illness within 28 days should seek medical advice.
Tick-borne encephalitis vaccine is recommended for travellers to forest and grassland areas of certain European countries, across Russia and eastern parts of Asia, mostly in altitudes lower than 1,500m.
- Licensed from 16 years of age
- First dose on day zero, with second dose given between one-to-three months and third dose given between 5–12 months after second dose
- Accelerated schedule: second dose may be given two weeks after first dose
- Lasts up to three years
- For 1–15 years of age — first booster is given three years after the third dose, then, every five years
- For 16–60 years of age — every five years for continued risk
- Over 60 years of age — every three years for continued risk
- Licensed from 1–15years
The information below is based on Public Health England recommendations; individual Summaries of Product Characteristics should be referred to for manufacturer recommendations regarding individual brands.
If a patient is suffering from an acute illness, immunisation should be postponed until they have recovered. Patients with minor infections without fever or systemic upset do not need to postpone their vaccination schedule.
Administration with other vaccines
Tick-borne encephalitis vaccine can be given at the same time as other routine and travel vaccines as long as they are administered at different sites.
Tick-borne encephalitis vaccine can be given to patients who are immunocompromised if they are travelling to an area of risk; however, it may not be as effective so additional doses may be required following serological tests. Specialist advice may be required.
Pregnancy and breast-feeding
No harmful effects due to tick-borne encephalitis vaccination during pregnancy or breastfeeding have been reported so it should be considered when clinically indicated.