TicoVac (Tick-bourne encephalitis vaccine)

How does it work?

TicoVac and TicoVac junior are vaccines against tick-borne encephalitis. They contain inactivated tick-borne encephalitis virus. The vaccine works by stimulating the body's immune response to the tick-borne encephalitis virus, without actually causing the disease.

When the body is exposed to foreign organisms such as viruses, the immune system produces antibodies against them. These antibodies help the immune system to recognise and kill the foreign organisms. Each foreign organism causes the body to produce a different type of antibody that only recognises that specific invader.

The antibodies formed remain in the body and recognise any future infection with the same organism. This allows the immune system to attack the organism rapidly and so prevent it causing disease. This protection from infections is known as immunity.

Immunity can be produced artificially by giving vaccines. A vaccine is a bacteria, bacterial toxin or virus that has been inactivated or altered in some way so that it does not cause disease. However, because the body recognises the vaccine as a foreign invader, it produces antibodies against it in the same way as it would against the genuine infecting organism. If the body then encounters the genuine infecting organism it is already prepared and can launch an attack against it rapidly.

Each organism stimulates the production of a specific type of antibody, so a different vaccine must be used for each disease. This tick-borne encephalitis vaccine stimulates the body to produce antibodies against the virus that causes tick-borne encephalitis. This virus is transmitted by bites from ticks found mainly in rural areas of Russia, Central and Eastern Europe and Japan. The vaccine is recommended for people travelling to high-risk areas, for example people working, walking or camping in warm forested areas of Central and Eastern Europe and Scandinavia, particularly from April to October when ticks are most prevalent.

The vaccine is given by injection into a muscle of the upper arm (intramuscularly). Three doses are needed. The second dose is given between one and three months after the first dose (but if necessary to acheive more rapid protection can be given after 14 days). The third dose should follow 5 to 12 months after the second dose. Two doses of the vaccine provide protection in 90 per cent of people, while almost 100 per cent of people should be protected after three doses. Ideally, the immunisation should be completed at least one month before travel.

Some vaccines remain effective for a lifetime, while others have to be updated after a few years. The three initial doses of this vaccine provide immunity against tick-bourne encephalitis for three years, after which time a booster dose will be needed to provide continued protection. Further boosters may then be needed every three years to provide continued immunity. This can be checked by measuring the levels of antibodies in the blood.

What is it used for?

  • Vaccination against tick-borne encephalitis.

Warning!

  • People over 60 years of age and people who have an underactive immune system, for example due to a genetic defect, disease such as HIV infection, or treatment with immunosuppressant medicines such as chemotherapy, high-dose corticosteroids, or immunosuppressants, for example used following an organ transplant, may not produce an adequate number of antibodies in response to this vaccine. As a result, the vaccine may be less effective in these people. Your doctor may want to take a blood test to measure the level of antibodies in your blood four weeks after your second dose, and give another dose if you haven't produced enough antibodies at this time. The third dose should then be given as normal. If you have previously had a vaccine against Japanese encephalitis, yellow fever or Dengue virus, you should let your doctor know, because these can affect the results of blood tests to check for antibodies.
  • As with all vaccines, this vaccine may not produce immunity in 100 per cent of people given the vaccine. You are less likely to be protected if the three doses of the vaccine are given at longer intervals apart than is recommended.
  • Tick bites can also cause infection with Borrelia bacteria, which cause Lyme disease. This vaccine only provides immunity against infection with the tick-borne encephalitis virus, and does not provide protection against Borrelia infection and Lyme disease.

Use with caution in

  • People with a non-severe allergy to eggs.
  • Allergy to latex.
  • Diseases caused by the body's immune system attacking healthy body tissue (autoimmune diseases, eg rheumatoid arthritis, multiple sclerosis).
  • Brain disorders.
  • TicoVac junior should be used with caution in children with a history of fits associated with fever (febrile convulsions), or a history of a very high temperature (fever) following vaccinations. This is because the vaccine can cause fever in children, particularly in young children after the first dose. Your doctor may recommend that you give your child a medicine such as paracetamol to prevent fever or lower the child's temperature if they get a fever after having the vaccine. Ask your doctor or pharmacist for advice.

Not to be used in

  • People with a severe allergy to eggs or chicken (those who have had an anaphylactic reaction after eating egg or chicken).
  • People allergic to formaldehyde, neomycin, gentamicin or protamine sulfate.
  • Sudden feverish illness. (The vaccine should be postponed until after recovery.)
  • TicoVac is not recommended for children under 16 years of age.
  • TicoVac junior is not recommended for children under one year of age.

This vaccine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction after having this vaccine, inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain vaccines should not be used during pregnancy or breastfeeding. However, other vaccines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before having any vaccine.

  • The safety of this vaccine for use during pregnancy has not been established. It is not recommended for pregnant women unless considered essential by your doctor, and the potential benefits are considered to outweigh any risks to the developing baby. Seek medical advice from your doctor.
  • It is not known if this vaccine passes into breast milk. It should be given with caution to mothers who are breastfeeding, and only if the potential benefit to the mother outweighs any risk to the nursing infant.

Side effects

Vaccines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this vaccine. Just because a side effect is stated here does not mean that all people having this vaccine will experience that or any side effect.

  • Pain or tenderness at the injection site.
  • Headache.
  • Fever (pyrexia), particularly in children aged under three years - see cautions above.
  • Loss of appetite in children.
  • Restlessness or difficulty sleeping in children.
  • Nausea and vomiting.
  • Pain in the muscles or joints.
  • Fatigue.
  • A general feeling of being unwell (malaise).
  • Swollen lymph nodes.
  • Swelling, redness or hardening of skin at the injection site.
  • Dizziness.
  • Visual disturbances.
  • Increased heart rate (tachycardia).
  • Diarrhoea.
  • Rash or itching.
  • Aggravation of autoimmune diseases.
  • Convulsion.
  • Allergic reaction.

The side effects listed above may not include all of the side effects reported by the vaccine's manufacturer.For more information about any other possible risks associated with this vaccine, please read the information provided with the vaccine or consult your doctor or pharmacist.

How can this vaccine affect other medicines?

People taking medicines that suppress the activity of the immune system, such as chemotherapy, high-dose corticosteroids, or immunosuppressants (for example used following an organ transplant), may not produce adequate numbers of antibodies in response to this vaccine. As a result, the vaccine may be less effective in these people.

If other vaccines are given at the same time as this one they should be administered into a separate site and preferably into a different limb.