Diphtheria causes throat and sometimes skin infections. Serious, life-threatening infections can be caused by the toxin produced by some diphtheria bacteria. The toxin attacks nerves, leading to paralysis. It also attacks the heart muscle (leading to heart failure) and the adrenal glands, which are needed to produce a number of important hormones such as cortisol and adrenalin.
Diphtheria used to be common in New Zealand, with a total of 794 deaths in the five years from 1917 to 1921. Fortunately, in part because of vaccination, diphtheria has disappeared from New Zealand. However, it is common in other parts of the world and is, therefore, only a plane ride away.
Children are usually immunised against diphtheria using an injection that also contains protection against tetanus and whooping cough. There is a primary course of three injections for babies, then further boosters throughout childhood and adulthood.
The childhood vaccination also usually contains protection against polio or Haemophilus influenzae (type b), safely covering a range of diseases in one appointment. You can learn more about immunisation programmes and the options available to you from your doctor or other health professional.
Adolescent/adult-type diphtheria vaccine, combined with the tetanus, pertussis (whooping cough) vaccines, is suitable for anyone aged 7 years or over. It has a smaller dose of the diphtheria vaccine and is known as dTap by health professionals.
Diphtheria vaccine is given together with:
- Tetanus, pertussis, polio, hepatitis B and Haemophilus influenzae type b (DTaP-IPV-HepB/Hib) vaccines at 6 weeks, 3 months, 5 months.
- Tetanus, pertussis and polio (DTaP-IPV) at 4 years.
- Tetanus, pertussis (whooping cough) (dTap) is given at age 11 years.
How good is the protection offered by the Diphtheria vaccine?
The full course of this vaccine offers good protection against diphtheria for 90 to 95% of people. Those who have been immunised against diphtheria may still carry the bacteria in their throats. This means that although they are protected, they can still pass the bacteria on to people who have not been immunised, and young babies who are too young to be fully vaccinated.
What about side effects?
Some people feel unwell for a little while after the diphtheria vaccine, e.g. fever or a headache. Some redness or swelling around the injection site can occur and is more likely after the 4th dose of DTaP vaccine. The adolescent/adult dTap vaccine contains a smaller amount of the diphtheria and pertussis toxins and is less likely to cause local redness or swelling. These reactions do go away on their own, causing no lasting problems. Very rare problems include nerve damage in the nerves going to the arms or legs. As with all vaccines, a severe allergic reaction (anaphylaxis) can occasionally occur.
