Diphtheria is a throat infection which can lead to breathing difficulties. Diphtheria was a common cause of death in children until the 1940s but is now very rare in New Zealand due to immunisation.


Diphtheria is a rare but serious disease caused by toxin-producing strains of Corynebacterium. The bacteria usually cause infection of the throat, but can also cause skin infections.

Diphtheria is highly contagious. It is spread by coughs and sneezes, or through close contact with someone who’s infected. Skin infections may be caused by traditional tattooing.

  • Sometimes a person has a mild case of diphtheria and they don’t realise they’re sick. They can still pass on the infection.
  • The bacteria cause a greyish membrane (like a skin) to form in the throat. This leads to difficulty in swallowing and breathing.
  • The bacteria produce a toxin (chemical) which affects the body and can lead to nerve paralysis and heart failure.
  • 5–10% of people with the disease die.


If you or your child has diphtheria, the symptoms will be:

  • fever
  • thick, grey-white coating at the back of the throat
  • sore throat
  • headache
  • difficulty breathing
  • difficulty swallowing
  • bad breath
  • sleepiness
  • swollen glands
  • bark-like cough.

If it affects your skin, it can cause:

  • pus-filled blisters on the skin
  • large ulcers surrounded by red, sore-looking skin.


The main treatments are:

  • antibiotics to kill the bacteria
  • medicine (antitoxin) to stop the effects of the toxins produced by the bacteria
  • thoroughly cleaning infected wounds.


The best protection is immunisation.It’s important to protect babies from diphtheria by getting them immunised on time. They’re not protected until they’ve had all 3 doses.

All babies in New Zealand can be immunised against diphtheria as part of their free childhood immunisations at 6 weeks, 3 months and 5 months old.

Booster doses are given to children when they’re 4 and 11 years old.


This disease is covered on the New Zealand Immunisation Schedule. The vaccines used are INFANRIX®- hexa, INFANRIX-IPV™ and Boostrix™.

Continuing protection

To ensure protection continues, a diphtheria booster is offered at 45 and 65 years of age.

Making a decision about immunisation

Risks associated with diphtheria

  • The bacterial toxin can lead to nerve paralysis and heart failure.
  • Between 5–10 infected people in 100 die.

Risks associated with the vaccine

  • Anaphylaxis occurs extremely rarely after diphtheria-containing vaccine is given.

Immunisation is your choice. If you have questions, talk to your doctor or practice nurse or call the Immunisation Advisory Centre free helpline 0800 IMMUNE (0800 466 863).

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