• Immunizing agent, active

Plague vaccine is an active immunizing agent used to prevent infection by plague bacteria. It works by causing your body to produce its own protection (antibodies) against the disease.

Plague is a serious disease that can cause death. It is caused by a germ called Yersinia pestis, and is spread most often by infected rodents and by the bites of infected fleas. Plague may also be spread by close person-to-person contact with infected persons (such as occurs with persons living in the same household) who may carry plague bacteria in their nose and throat. Some infected persons do not appear to be sick, but they can still spread the germ to others.

If you are traveling to plague-infected areas of Africa, Asia, Latin America, or the western third of the United States, plague vaccine may help prevent plague infection. However, plague vaccine does not provide 100% protection. Therefore, it is very important to avoid contact with domestic and wild animals that may be infected, even if you have received the vaccine. To reduce your chance of getting plague from the bites of infected fleas, use insect repellent on exposed parts of your body, such as legs and ankles. Also apply DEET or another insecticide to clothes and outer bedding according to manufacturers' directions.

Plague vaccine is to be administered only by or under the supervision of a doctor. It is available in the following dosage form:

Parenteral
• Injection (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For plague vaccine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to plague vaccine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies on the effects of plague vaccine in pregnancy have not been done in either humans or animals.

Breast-feeding—This vaccine has not been reported to cause problems in nursing babies.

Children—Children and teenagers

Studies on plague vaccine have been done only in adult patients between the ages of 18 and 61, and there is no specific information comparing use of plague vaccine in children and teenagers younger than 18 years of age with use in other age groups. Although there is no specific information comparing use of plague vaccine in children and teenagers younger than 18 years of age with use in other age groups, this vaccine is not expected to cause different side effects or problems in children or teenagers than it does in adults.

Older adults—Studies on plague vaccine have been done only in adult patients between the ages of 18 and 61, and there is no specific information comparing use of plague vaccine in persons 61 years of age and older with use in other age groups. Although there is no specific information comparing use of plague vaccine in the elderly with use in other age groups, this vaccine is not expected to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

• Previous sensitivity reaction to plague vaccine—Use of plague vaccine is not recommended

• Severe illness with fever—The symptoms of the condition may be confused with the side effects of the vaccine

Dosing—

The dose of plague vaccine will be different for different patients. The following information includes only the average doses of plague vaccine.

• For injection dosage form:
  • For prevention of plague:
    • Adults, teenagers, and children—The first dose, injected into a muscle, followed by a second dose 1 to 3 months later and a third dose 5 to 6 months after the second dose.

To get the best possible protection against plague, you should complete the vaccine dosing schedule before you travel to areas where you may be exposed to plague.

If you will be traveling regularly to parts of the world where plague is a problem, you should get a booster (repeat) dose of the vaccine every 6 months.

Along with its needed effects, a vaccine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Get emergency help immediately if any of the following side effects occur:

• Rare
  • Difficulty in breathing or swallowing;  hives;  itching, especially of soles or palms;  reddening of skin, especially around ears;  swelling of eyes, face, or inside of nose;  unusual tiredness or weakness (sudden and severe) 
  
  

Other side effects may occur that usually do not need medical attention. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Fever;  general feeling of discomfort or illness;  headache;  joint pain;  muscle pain;  nausea and/or vomiting;  pain, redness, or swelling at place of injection;  swollen glands 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.