Questions & Answers
Diphtheria - The Vaccine
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  1. Is there a treatment for diphtheria?
    Diphtheria is treated with both antibiotics and with diphtheria antitoxin. Antitoxin is the name for antibodies that neutralize toxins. Diphtheria antitoxin is produced in horses and was first used in the United States in 1891. Antitoxin is not effective against toxin that is already attached to the body's tissues, but antitoxin will neutralize circulating poison and prevent the disease from getting worse. The patient should be tested for antitoxin sensitivity (because it is horse-derived) before administration.

  2. What kind of vaccine prevents diphtheria?
    The diphtheria vaccine consists of a modified toxin called a toxoid. The vaccine is made by growing the bacteria in a liquid medium and purifying and inactivating the toxin.

  3. When did the diphtheria vaccine become available?

    The first toxoid against diphtheria was developed around 1921, but was not widely used until the 1930’s. In the 1940’s, diphtheria was combined with pertussis vaccine and tetanus toxoid to make the combination DTP (or DTaP) vaccine for children.

    Diphtheria toxoid (DT) is also combined in other vaccines:

    • DT vaccine for the few children who cannot receive pertussis vaccine.
    • Td vaccine for people 7 years or older (tetanus toxoid and a reduced dose of diphtheria toxoid).
    • Tdap vaccine for people 10 years or older (tetanus toxoid with reduced doses of diphtheria toxoid and acellular pertussis vaccine).
    • Diphtheria toxoid is not available as a single vaccine.

  4. Who recommends this vaccine?
    The Centers for Disease Control and Prevention (CDC), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP) all recommend this vaccine.

  5. How safe is this vaccine?
    Serious reactions after immunization are rare. The most common reactions are soreness, redness, and swelling at the injection site. Other possible reactions may include fussiness, mild fever, loss of appetite, tiredness, and vomiting. The use of the more purified DTaP vaccine, instead of DTP has decreased even these mild reactions.

  6. Can the vaccine cause diphtheria?

  7. Do I need to be immunized if I had diphtheria?
    Yes. Unfortunately, some people who suffer diphtheria illness do not produce enough antitoxin to prevent future illness. It is recommended that people recovering from diphtheria be immunized.

  8. What's the difference between DT and Td vaccines?
    The difference is the amount of diphtheria toxoid contained in each dose. Pediatric DT ("big D") contains 3 to 5 times more diphtheria toxoid than the adult Td ("little d"). DT is used for the few children who cannot receive the pertussis component of the DTaP vaccine, and Td is used for adults and children seven years of age and older who need booster doses of diphtheria and tetanus toxoid.

  9. Should adults who weren't immunized as children receive this vaccine as adults?
    Yes. Adults or children seven years and older without documentation of tetanus and diphtheria vaccination should receive a primary series of three doses of Tetanus-diphtheria toxoid (Td). The first two doses should be separated by 4 to 8 weeks, and the third dose given 6 to 12 months after the second dose. Td will protect you from diphtheria infection as well as tetanus.