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Public Health - Seattle & King County

Injectable typhoid vaccine

What is typhoid fever?

Typhoid fever is a disease caused by the typhoid bacillus, Salmonella typhi. It is spread through contaminated food and water or by close contact with an infected person. It occurs worldwide, and while uncommon in the United States, cases are reported every year, especially from travelers. The highest disease rates occur in Chile, Peru, India, Pakistan, Indonesia, Nigeria, and North Africa, and other countries where difficulties in sanitation and unprotected water supplies exist. Symptoms may include fever, headache, listlessness and body aches, loss of appetite, and stomach problems often beginning with constipation, followed by serious diarrhea. Symptoms can be severe and prolonged. In serious illness, 10 out of 100 infections (10%) may result in death. If treated with appropriate antibiotics, this may be reduced to less than 1%.

Injectable typhoid vaccine

One injectable typhoid vaccine is currently available for use in the United States: Vi polysaccharide vaccine (ViCPS). ViCPS can be given to adults and children as young as 2 years of age. ViCPS vaccine is estimated to be about 74% effective in preventing disease. (A heat-treated inactivated typhoid vaccine that was wide used for many years is no longer available.)

Typhoid vaccine is recommended for:

  • Travel to areas where typhoid fever is a problem or where poor food and water sanitation exist.
  • Intimate exposure to a known typhoid carrier, such as would occur with continued household contact.

Since typhoid vaccine cannot provide 100% protection, receiving vaccine is not a substitute for careful selection of food and drink (e.g. drink only bottled or boiled water and eat only thoroughly cooked food served hot).

Immunization schedule for Vi Polysaccharide vaccine (ViCPS)

  • Initial series is a single injection.
  • A booster dose may be given every two years for continued or repeated exposure.
  • A booster dose may be given every two years for continued or repeated exposure.
  • A booster dose may be given every two years for continued or repeated exposure.

Possible side effects of the vaccine

Vi polysaccharide vaccine may cause redness or swelling where the vaccine was given, as well as fever and headache. These side effects result less often with the Vi polysaccharide vaccine compared to the inactivated vaccine.

You should not receive the vaccine today if you have:

  • An acute illness with a fever.
  • An acute infection of your gastrointestinal system.
  • A history of severe allergic reactions following a previous dose of injectable typhoid vaccine.

Use of injectable typhoid vaccine during pregnancy

Specific information concerning use of injectable typhoid vaccine during pregnancy is not available. However, it may be used when risk of exposure to typhoid fever is high.


If the person who received the vaccine experiences any of the side effects mentioned above and visits a doctor, hospital, or clinic after vaccination, please report it to the Health Department by calling 206-296-4774.