Diphtheria outbreaks a reminder to stay up to date with vaccination

The Australian Medical Association is urging Australians to check that they and their families are up to date with their vaccinations, as diphtheria spreads to more states. 

There have been 223 diphtheria notifications in 2026 as of 19 May, already exceeding any full calendar year recorded since national reporting began, with public health authorities warning of increasing notifications since late 2025.

Diphtheria is a serious bacterial infection that can affect the nose, throat, airways or skin. In severe cases, respiratory diphtheria can obstruct breathing, and the toxin can cause life-threatening complications, including heart and nerve damage. 

The Australian Immunisation Handbook recommends routine vaccination as a primary course for infants and routine boosters for adolescents and adults in certain circumstances, because vaccination remains the strongest protection against this preventable disease. The primary course for infants is one dose at two, four and six months old. 

Australian Medical Association President Dr Danielle McMullen said the rise in diphtheria cases was a serious reminder of the importance of vaccines. 

“Immunisation is one of the greatest achievements in modern medicine, but when vaccination rates fall, serious diseases, which we had largely eliminated, can make a comeback,” Dr McMullen said. 

“We are seeing that risk play out with diphtheria, and it is a timely reminder for Australians to check they are up to date with their vaccines and to talk to their usual GP if they have questions.”

“Through the federal AMA’s national Have the JABCHAT campaign, we are encouraging Australians to speak with their usual GP about any questions or concerns they may have about vaccines,” she said. 

“We developed this campaign to encourage people to get qualified, personalised and confidential advice from their trusted doctor.

“We know many Australians are turning to AI tools and online searches for health advice. But those tools can’t look at your medical history, understand your personal risks, or give you the context you deserve — and they’re not always accurate or validated. AI can give you an answer, but it can’t give you your answer.

“Our campaign is designed to encourage and support Australians, who feel unsure or overwhelmed, to access advice they can trust. Australians deserve advice that is trustworthy, tailored to them and delivered in a confidential setting — and that’s exactly what a conversation with a doctor provides.”

The AMA is encouraging parents, carers and adults to review their vaccination status, including any booster doses they may be due for, and to book an appointment with their GP to discuss the vaccinations recommended for them and their family. Catch-up vaccinations may be available for families with missed or delayed vaccinations.

More advice on Diphtheria and vaccines is available on the Australian Centre for Disease Control website.