A Growing Concern: Chikungunya and the Race for a Vaccine
The Rise of Chikungunya Infections in Australia
Chikungunya, a mosquito-borne virus, is on the rise in Australia, with an increasing number of cases reported among international travelers. This trend has sparked the development of a vaccine by researchers in Queensland, potentially putting this virus on the radar of many Australians.
According to the Australian Centre for Disease Control, the number of chikungunya virus infections in Australia has been steadily climbing. In 2025, there were 165 reported cases, a significant increase from the 69 cases recorded in 2024. Victoria took the lead with 80 cases, followed by NSW with 29. This trend is a cause for concern, especially considering the global increase in cases in 2025.
Understanding the Threat
Chikungunya is not native to Australia, but it is considered a major global health threat. Outbreaks have been reported across Africa, Asia, the Americas, the Western Pacific, and Europe. The virus primarily targets joint tissue, muscle fibers, and connective tissue, leading to intense inflammation and tissue damage. Common symptoms include fever, severe joint and muscle pain, headaches, rashes, and joint swelling.
The disease can be particularly severe in older adults, individuals with underlying conditions like cardiovascular disease or diabetes, and newborns. In rare cases, infection during pregnancy can result in severe illness in infants. Currently, there is no specific antiviral treatment, and management focuses on supportive care.
The Risk of Local Transmission
While chikungunya virus has not been detected in Australian mosquitoes, the primary mosquito vectors are present in northern Queensland and the Torres Strait. This raises the risk of local transmission if the virus is introduced. Mosquito expert Associate Professor Cameron Webb emphasizes that the overwhelming majority of cases are acquired overseas.
Travelers Beware: The Sneaky Mosquitoes
Professor Webb highlights one of the biggest risks for travelers regarding chikungunya infection: the behavior of mosquitoes carrying the virus. These mosquitoes, particularly the yellow fever mosquito that spreads dengue, preferentially bite people during the day, unlike the typical Australian mosquitoes that are more active in the afternoon and evening. Additionally, the numbers of these mosquitoes are significantly higher in popular holiday destinations like Indonesia, Southeast Asia, and the Pacific, increasing the risk of infection for travelers.
Defending Against Bites
One of the best defenses against mosquito bites is a quality repellent. Professor Webb recommends taking mosquito repellent from Australia when traveling. He emphasizes the importance of applying it throughout the day, especially when outdoors, as these mosquitoes tend to feed around the feet and lower legs. Developing a habit of applying repellent regardless of the number of mosquitoes buzzing about is a good practice to adopt.
A Vaccine on the Horizon
But here's where it gets controversial... Researchers at Queensland's Griffith University are making significant progress in developing a vaccine for chikungunya. The research team, led by Professor Bernd Rehm, has engineered Escherichia coli to assemble synthetic biopolymer particles that mimic the surface of the chikungunya virus. In preclinical studies, these particles successfully induced a protective immune response without the need for an adjuvant.
The experimental vaccine, known as adjuvant-free E2-BP-E1 biopolymer particles, is designed to display chikungunya antigens in a structure similar to the native virus. This design allows immune cells to recognize and absorb the particles efficiently, prompting a robust antiviral response without causing infection. Professor Rehm explains, "The immune system recognizes the particles as a virus, but without inducing infection. This allows immune cells to efficiently engage and mount a protective response."
A key concern with chikungunya is the high rate of chronic morbidity, with up to 60% of patients experiencing persistent joint pain that can last for months or years, often resembling rheumatoid arthritis. Professor Rehm suggests that immune-mediated damage may continue even after the virus has been cleared, leading to long-term health issues.
Following the success of their current study, the Griffith team plans to progress the vaccine into clinical development. The next phase will involve early-stage clinical trials to assess safety, followed by efficacy studies. The findings have been published in the journal Biomaterials.
So, what do you think? Is the development of a vaccine the answer to controlling the spread of chikungunya? Or are there other strategies we should be focusing on? Share your thoughts in the comments below!
