Australia is grappling with its most significant surge in whooping cough cases in 35 years, a concerning development that has health officials on high alert. In 2024 and 2025, the country recorded a staggering 82,513 cases of the illness, marking the highest number since records began in 1991. This surge raises critical questions about the factors driving the increase and the measures needed to protect the population.
Whooping cough, also known as pertussis or the “100-day cough,” is a potentially fatal respiratory illness characterized by severe coughing episodes. It spreads easily from person to person and poses a particular threat to infants. The recent rise in cases has prompted health authorities to investigate the reasons behind this alarming trend and to emphasize the importance of vaccination.
Understanding Whooping Cough
Whooping cough is caused by the bacterium Bordetella pertussis and is transmitted through close contact with infected individuals, often via coughing and sneezing. The illness begins with early symptoms resembling a common cold, such as a runny nose or sore throat, known as the “catarrhal phase.” This is followed by persistent coughing spells that can last between six and ten weeks. In infants and children, these coughing fits often produce a distinctive “whoop” sound when inhaling, giving the disease its name.
The illness can be particularly severe in newborns and infants, with approximately one in 125 babies under six months succumbing to complications like pneumonia or brain damage. Household contacts, particularly parents, are frequently the source of infection, with more than 50% of cases traced back to them. Infants can also contract the disease from siblings and healthcare workers.
The Role of Vaccination
Vaccination remains the most effective defense against whooping cough. In Australia, the whooping cough vaccine is administered as part of a combination vaccine with diphtheria and tetanus, included in routine infant and childhood immunization schedules. Additionally, Year 7 students receive a booster dose. Pregnant women are advised to vaccinate during each pregnancy to enhance antibody production and transfer to their unborn child, offering protection to infants too young to be immunized.
A 2025 study from Denmark found vaccination during pregnancy to be 72% effective against laboratory-confirmed whooping cough.
Despite the availability of vaccines, low immunization rates among children and adolescents remain a significant concern. Recent data indicates that Australia’s childhood immunization rate in 2024-25 was the lowest in a decade. Furthermore, only about one-fifth of adults over 50 are up to date with their whooping cough vaccinations, having received a booster within the last ten years.
Why the Surge?
Whooping cough is notoriously difficult to control due to the waning immunity acquired through vaccination or natural infection, leading to epidemics every two to three years. The disease is most commonly diagnosed using PCR testing of a throat swab, a method routinely used since the early 2000s.
In 2024, Australia detected 57,257 whooping cough cases, the highest notification rate since records began. This surge reflects both a genuine increase in prevalence and heightened awareness and testing. The COVID-19 pandemic likely played a role, as public health restrictions disrupted the usual epidemic cycle, leaving many children without the typical immune “boost” from vaccination and exposure to the bacteria. This vulnerability was exacerbated when social distancing measures were lifted.
In 2025, whooping cough remained widespread, with 25,256 cases reported. All age groups were affected, but school-aged and preschool-aged children had the highest notification rates.
Looking Ahead
Unfortunately, whooping cough is unlikely to disappear soon. However, timely vaccination across all ages is crucial to curbing its spread and protecting vulnerable populations. Australia’s national vaccine regulator conducts annual safety checks on whooping cough vaccines, confirming their safety and efficacy for people of all ages.
As health authorities continue to monitor the situation, the emphasis remains on increasing vaccination rates and public awareness. The recent surge serves as a stark reminder of the importance of maintaining high immunization coverage to prevent future outbreaks and protect the most vulnerable members of society.
This material, courtesy of The Conversation, has been edited for clarity, style, and length. Mirage.News does not take institutional positions or sides, and all views, positions, and conclusions expressed herein are solely those of the author(s).
