A dengue vaccine is now available for travellers. Here’s what you need to know

Dengue is a viral illness spread by mosquitoes that can cause fever, headache, body aches, nausea, and rash. There is no specific treatment, and most people recover within one to two weeks. However, some individuals may experience severe illness, require hospitalization, or even face fatal outcomes. The dengue vaccine Qdenga is now available in Australia for travellers, providing an additional method of protection. Deciding whether to receive the vaccine is not always straightforward and depends on various factors.

Dengue is prevalent in tropical regions, with more than 1,900 cases reported in Australia in 2025, mostly among returned travellers. Indonesia, Thailand, and India are the most common sources of dengue infection for Australians. Although dengue outbreaks are rare in Australia due to public health measures, the risk is higher for travellers. Climate change may also increase the likelihood of outbreaks in certain areas.

Developing a dengue vaccine has been challenging due to the need for protection against all four virus types without increasing the risk of severe disease. Qdenga, a weakened dengue virus vaccine, has been administered to millions worldwide with no increased risk of severe dengue observed. In a study of children and teenagers, Qdenga prevented approximately 80% of illness and over 95% of hospitalisations in the first year. Side effects are generally mild and last one to three days, with most travellers experiencing them.

However, Qdenga is not suitable for everyone, such as those with weakened immune systems or pregnant individuals. Its effectiveness varies depending on previous dengue exposure, with strong protection against types one and two but uncertainty regarding types three and four. Recommendations for vaccination differ among countries based on individual circumstances.

In Australia, the vaccine is recommended for travellers aged four or older who have had dengue before or those who expect prolonged or repeated exposure to dengue-prone regions.

Preventing dengue through mosquito bite avoidance remains crucial, regardless of vaccination status. Aedes aegypti mosquitoes, the primary transmitters of dengue, are most active during the day, often biting around the lower legs. Travellers should use insect repellent, wear long pants, shoes, and consider using bed nets, particularly when sleeping during the day in areas with inadequate insect screens.

Qdenga costs around AUD$300 for two doses and is recommended for specific Australian travellers based on their individual risk factors and travel plans.