Australia recorded 223 diphtheria notifications as of 19 May 2026, already exceeding any previous full-year total since national reporting began. The Australian Medical Association is urging Australians to check their vaccination records and speak with their GP if they are unsure about booster doses.
Australians are being urged to check that they and their families are up to date with vaccinations as diphtheria notifications continue to rise, with health experts warning that the disease remains a serious threat despite being preventable.
There have been 223 diphtheria notifications recorded in Australia in 2026 as of 19 May, already exceeding any full calendar year recorded since national reporting began. Public health authorities have also warned of increasing notifications since late 2025.
The reminder may be particularly relevant for families with overseas immunisation records, including Filipino–Australian households and other migrant communities, where keeping track of vaccinations across different health systems can sometimes be difficult.
What is diphtheria?
Diphtheria is a serious bacterial infection that can affect the nose, throat, airways or skin. It is caused by bacteria that can produce toxins, or poisons, that damage the body.
It can spread through coughs, sneezes or close contact. In severe cases, it can obstruct breathing, while toxins from the infection can cause serious complications, including heart and nerve damage.
Vaccination programs have greatly reduced cases over the years, which means many Australians today may never have seen a case of the disease. However, it can still be dangerous, particularly for people who are unvaccinated or not fully protected.
According to the Australian Immunisation Handbook, routine vaccination is recommended as a primary course for infants, with doses given at two, four and six months of age. Booster doses are also recommended for adolescents and adults in certain circumstances.
Vaccination remains the main protection against the disease.
Why experts are concerned
Australian Medical Association President Danielle McMullen said the rise in cases was a reminder of the importance of vaccinations.
“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 come back,” 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 and to talk to their usual GP if they have questions,” she said.
The AMA said its national Have the JABCHAT campaign encourages Australians to speak with their usual GP if they have questions or concerns about vaccines.
“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,” Dr McMullen said.
“We developed this campaign to encourage people to get qualified, personalised and confidential advice from their trusted doctor,” she said.
“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,” Dr McMullen said.
“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,” she said.
Who should check their records?
The AMA is encouraging parents, carers and adults to review their vaccination status, including any booster doses they may be due for.
For families with overseas immunisation records, this may include checking whether children have received all doses recommended in Australia or whether catch-up vaccinations may be needed.
People who may have missed or delayed vaccinations could also be eligible for catch-up vaccinations.
