Dengue fever was covered in depth in a previous Priory Pharmacy blog. That article covered the symptoms, how the Aedes aegypti mosquito spreads the disease, and the global impact.
This article focuses on Qdenga, the dengue vaccine approved by the UK MHRA in 2022. Qdenga is the first dengue vaccine suitable for people who have never had dengue before. It is now available at travel clinics, including Priory Pharmacy in York.
For travellers planning visits to Southeast Asia, South Asia, the Caribbean, or Central and South America, Qdenga is a useful addition to pre-travel preparation.
Why Dengue Vaccination Has Been Difficult
Dengue is caused by four different virus types, known as DENV-1 to DENV-4.
If you have had dengue once, a later infection with a different type can cause more severe illness. This is called antibody-dependent enhancement (ADE).
The first licensed dengue vaccine, Dengvaxia, was approved in 2015. It was only safe and beneficial for people who had already had dengue. In people who had never had dengue, it increased the risk of severe dengue after a later natural infection. This made it unsuitable for most UK travellers.
How Qdenga Works and What the Evidence Shows
Qdenga (also called TAK-003, made by Takeda) is a live vaccine that protects against all four dengue types. It is based on a DENV-2 backbone, with genes from DENV-1, DENV-3, and DENV-4 added in.
It was approved by the UK MHRA in 2022 for people aged four and above, including those who have never had dengue.
The TIDES trial:
- A phase 3 trial called TIDES enrolled over 20,000 people across eight countries
- It was randomised, double-blind, and placebo-controlled
- Results showed about 61% overall efficacy against confirmed dengue across DENV-1 and DENV-2
- Results showed about 84% efficacy against dengue that required hospitalisation
Importantly, unlike Dengvaxia, the TIDES trial did not show an increased risk of severe dengue in people who had never had dengue before. This is the key finding that makes Qdenga appropriate for typical UK travellers.
Schedule and Practical Considerations
Qdenga is given as two doses, three months apart, injected under the skin.
Both doses should ideally be completed before you’re exposed to dengue.
If your travel dates don’t allow you to finish the full course before you leave, the first dose still gives some protection particularly against dengue requiring hospitalisation. The second dose can then be given after you return.
Qdenga is available privately. It is not currently funded by the NHS.
Qdenga Is an Addition, Not a Replacement
Qdenga adds to mosquito bite avoidance — it does not replace it.
- Aedes aegypti mosquitoes bite during daylight hours
- DEET repellent should be applied to all exposed skin throughout the day, regardless of vaccination status
- Qdenga does not protect against other diseases spread by Aedes mosquitoes, including Zika or chikungunya
A full travel health consultation makes sure your complete travel health plan is right for your destination and itinerary.
Who Should Consider Qdenga at Priory Pharmacy York
Qdenga is recommended for travellers aged four and above who are planning travel to dengue-endemic regions, including:
- Southeast Asia Thailand, Indonesia, Vietnam, Philippines, Malaysia
- South Asia — India, Sri Lanka
- The Caribbean
- Central America
- Parts of South America
Qdenga is not suitable for people who are pregnant, as no studies have been done, or who are breastfeeding.
If you are pregnant, planning a pregnancy, or currently breastfeeding, this should be discussed during your travel health consultation. This allows alternative options and mosquito bite prevention measures to be considered.
Whether Qdenga is the right choice for you — taking into account trip duration, activities, and risk tolerance — is assessed during a travel health consultation at Priory Pharmacy in York.
This article is for general information only and does not constitute individual clinical advice.
Please book a travel consultation at Priory Pharmacy in York to discuss your individual requirements before travel.
Frequently Asked Questions
Qdenga is a live, attenuated vaccine designed to help prevent dengue disease. It is licensed in the UK for individuals aged 4 years and over, although whether it is suitable for a particular traveller depends on their individual circumstances and travel risk assessment.
In UK travel health guidance, Qdenga may be considered for certain travellers aged 4 years and over who have had dengue infection in the past and are travelling to an area where dengue is a risk. In exceptional circumstances, vaccination may also be considered for some people without a previous dengue infection following specialist assessment. A travel health professional can assess your individual circumstances.
The standard Qdenga vaccination schedule consists of two doses given three months apart. Travellers should also continue to protect themselves against mosquito bites, as vaccination does not remove the need for mosquito bite prevention measures.