Typhim Vi (Typhoid vaccine)

How does it work?

Typhim Vi vaccine contains fragments of inactivated Salmonella typhi bacteria (the bacteria that cause typhoid). It works by stimulating the body's immune response to the typhoid bacteria, without actually causing the disease.

When the body is exposed to foreign organisms such as bacteria, 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 typhoid vaccine stimulates the body to produce antibodies against the bacteria that cause typhoid. The vaccine is usually given by injection into a muscle (intramuscularly) for example in the upper arm.

This vaccine is recommended for people travelling to areas with a high risk of typhoid. It should be given at least two weeks before travel to the high risk area. The vaccine provides immunity against typhoid for about three years. To provide continued protection against typhoid a booster injection is needed every three years.

What is it used for?

  • Vaccination against typhoid in adults and children aged two years and over.

Warning!

  • As with all vaccines, this vaccine may not produce immunity in 100 per cent of people given the vaccine. You should still observe strict food, water and personal hygiene measures to avoid the disease. These include washing hands before eating or preparing food, only drinking boiled or sterilised water, avoiding ice cubes in drinks unless you know they were made from 'safe water', eating only freshly prepared hot food that has not been allowed to stand at room temperature for many hours, and avoiding raw fruit and vegetables unless you have peeled them yourself. Be careful eating food from street stalls. Measures such as these can also protect you from paratyphoid, hepatitis A, cholera and other types of travellers diarrhoea. Ask your pharmacist for more advice.
  • 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.
  • Children under two years of age may also not produce an adequate number of antibodies in response to this vaccine. As a result, the vaccine may be less effective in this age group. Children aged between one and two years should be immunised if the risk of typhoid fever is considered high, but immunisation is not recommended for infants under 12 months.

Use with caution in

  • Allergy to formaldehyde.
  • People at risk of bleeding after an injection into a muscle, for example due to blood clotting disorders such as haemophilia or a reduced platelet count in the blood (thrombocytopenia).

Not to be used in

  • Sudden feverish illness. (The vaccine should be postponed until after recovery.)
  • People who have previously had a life-threatening allergic reaction to a typhoid vaccine.

This vaccine should not be given if you are allergic to one or any of its ingredients. Please inform the doctor or nurse giving the vaccine if you have previously experienced an allergic reaction to a typhoid vaccine.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, it does not mean that all people having this vaccine will experience that or any side effect.

  • Pain, redness or hardening of the skin around the injection site.
  • Fever (pyrexia).
  • Headache.
  • Pain in the muscles or joints.
  • Fatigue.
  • Nausea and vomiting.
  • Diarrhoea.
  • Abdominal pain.
  • 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.

This vaccine may be given at the same time as other common vaccines, for example yellow fever, diphtheria, tetanus, polio, rabies, meningitis A+C, hepatitis A and hepatitis B, but if so should be administered into a separate site.

Other typhoid vaccines

Typherix Vivotif