Impact of lack of immunisation against diphtheria in the Australian military during the Second World War.

Immunisation has been critically important to military medicine. During the Second World War, Australian soldiers were immunised against smallpox, typhoid and tetanus. A conscious decision not to immunise soldiers against diphtheria was taken, although the toxoid had been available in Australia since 1927. This was due to the large number of soldiers thought to have pre-existing immunity (Schick test negative) and adverse events experienced during mass immunisation. Diphtheria became an operational problem in Palestine in 1940. Epidemics of diphtheria in prisoner of war (POW) camps had lethal outcomes due to lack of anti-sera. Many tropical ulcers likely had a component of diphtheria infection. Post-war problems with diphtheria have largely been limited to under-immunised populations in refugee situations, although diphtheria is again being seen in Australian civilians. Toxoid immunisation against environmental pathogens such as diphtheria and tetanus must be maintained to avoid preventable disease during any future war or disaster.