Typhoid Vaccination

Transmission

The disease is transmitted from human to human via ingesting contaminated food or drinking water or through poor personal hygiene, such as lack of hand washing. The bacteria is found in the faeces of infected individuals and 2-5% of those infected become long term carriers and excrete the bacteria in their faeces.

Symptoms

The incubation period is 10 to 20 days and depends on, among other things, how large a dose of bacteria has been taken in.
In the mild disease, the bacterium is eliminated very early in the course of the disease and there are perhaps only mild symptoms.

Symptoms can include high fever, diarrhoea or constipation, headache, rash and in severe disease multi-organ failure can occur.  If untreated, the death rate is 20%, whereas prompt antibiotic treatment reduces this to less than 1%.

Treatment

Typhoid is treatable with antibiotics administered early on. Supportive treatment, such as rehydration are also important.

Prevention

Food and water hygiene measures while travelling are important as is maintaining personal hygiene.

Vaccination is available to those at risk of typhoid fever.

The typhoid vaccine is made from inactivated protein from the bacteria. It cannot cause infection in the vaccinated individual and nor is the vaccinated individual infectious to others. The inactivated vaccine is effective from 7 days and provides around 75% protection against the illness. There is a live vaccine that is taken orally, which is 50-60% effective. However, this is rarely indicated as it requires 3 doses, can only be given from 6 years of age and is not as effective as the inactivated injection.

Inclusions

Adults and children from 2 years of age travelling to countries endemic for or with a high risk of typhoid infection.

Booster Doses

There is no booster vaccination for typhoid, instead a new vaccination should be given every 3 years for ongoing risk.

The inactivated vaccine should not be given if:

• There is a history of severe allergic reaction to previous dose of typhoid vaccine or any of the components of the vaccine.
• In illnesses with fever above 38.5 degrees Celsius.

Pregnancy

There is no specific data on the safety of the inactivated typhoid vaccine during pregnancy. However, inactivated vaccines have not been shown to cause harm during pregnancy. Therefore, the vaccine can be  administered to pregnant women who are at significant risk of exposure to Typhoid during travel following a careful risk assessment.

Breast Feeding

There is no specific data on the safety of the inactivated typhoid vaccine when given to breast feeding mothers. However, inactivated vaccines have not been shown to cause harm when given to breast feeding mothers.  Therefore, the vaccine can be admisnieterd to pregnant women who are at significant risk of exposure to Typhoid during travel following a careful risk assessment.

Common Side Effects

Local reactions at injection site-pain, redness, swelling.

Fever, nausea and vomiting, abdominal pain, headache and muscle ache can occur after vaccination and are normally short lived.

Interactions with Other Vaccines

The inactivated typhoid vaccien doe snot interact with other vaccines and can be given at the same time as other vaccines, including hepatitis A, hepatitis B, rabies and yellow fever.

1) What are the contents of the inactivated Typhoid vaccines?

Typhim Vi contains the following ingredients

• Phenol (preservative)
• Sodium Chloride
• Disodium phosphate dihydrate
• Sodium dihydrogen phosphate dihydrate
• Water for Injections

The vaccine does not contain

• Egg products
• Thiomersal
• Latex
• Gelatin

2) Why can the vaccine not be given to children under 2 years?

The reason for this is that the typhoid vaccine is a polysaccharide vaccines and children under 2 years do not mount a good immune response to the vaccine. Therefore, they are not as effective.

3) Why is a new vaccination required after 3 years?

The immunity from the typhoid vaccine wanes over this period of time. Therefore, if there is further risk of exposure due to travel, a new vaccination is required to increase the protection levels.

4) How effective is the Typhoid vaccine?

The inactivated vaccine is around 75% effective. This may be less if a large number of bacteria is ingested. Therefore, it is important that in addition to vaccination, you are scrupulous with food and water and hand hygiene while travelling.