The Basics
What Causes Dengue Fever?
Dengue is a viral infection transmitted to humans through the bite of infected mosquitoes, primarily the Aedes aegypti and Aedes albopictus species. It is caused by one of four distinct dengue virus serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). It is widely known as “breakbone fever” due to the severe muscle and joint pain it can cause. Dengue is most common in tropical and subtropical climates worldwide.
Vaccination Overview
The Dengue Vaccine (Qdenga)
| Feature | Details |
| Name of Vaccine | Qdenga (Live-attenuated vaccine). |
| Number of Doses | A two-dose series. |
| Schedule | The second dose is given 3 months after the first. |
| When to get it | Ideally, start the course at least 3.5 months before travel to ensure full protection. |
| How it is given | Administered as a subcutaneous injection (usually in the upper arm). |
| Suitable Age | Typically licensed for use in individuals aged 4 years and older. |
Safety & Side Effects
What to Expect After Vaccination
The vaccine contains a weakened version of the virus, so some people may experience mild “viral” symptoms as their immune system responds:
- Injection Site: Redness, pain, and swelling at the site of the shot.
- Common Signs: Headache, muscle aches (myalgia), and a general feeling of being unwell.
- Less Common: A mild fever or a faint rash within a few days of the injection.
Recognising Symptoms
Symptoms of Dengue Fever
Symptoms typically begin 4 to 10 days after a mosquito bite and last for 2 to 7 days.
High Fever: A sudden, high temperature (often 40°C/104°F).
Severe Pain: “Retro-orbital” pain (pain behind the eyes), severe headache, and intense joint/muscle pain.
The “Dengue Rash”: A flat, red rash that may cover much of the body.
Nausea & Vomiting: Persistent upset stomach and loss of appetite.
Warning Signs (Severe Dengue): Severe abdominal pain, persistent vomiting, bleeding gums, or rapid breathing. Severe Dengue is a medical emergency.
Additional Precautions
Mosquito Bite Prevention
Because the Aedes mosquitoes that carry Dengue are day-biting (active from dawn to dusk), bite prevention must be practiced all day long:
Repellent: Use a high-quality repellent containing 30–50% DEET.
Clothing: Wear loose-fitting, long-sleeved clothing. Treating clothes with permethrin provides an extra layer of safety.
Environment: Avoid areas with stagnant water (like buckets or flower pots), where mosquitoes breed.
Room Safety: Stay in accommodation with air conditioning or well-fitted insect screens.
FAQ
Do I need to have had Dengue before to get the Qdenga vaccine?
No. Unlike older vaccines, Qdenga is approved for use in individuals regardless of whether they have previously been infected with the Dengue virus.
Can I get Dengue more than once?
Yes. Because there are four different types of the virus, you can be infected up to four times. A second infection with a different type often carries a higher risk of severe disease.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. While we strive to provide accurate health information, it is not a substitute for the professional judgment of a healthcare provider. Always seek the advice of your physician or other qualified health professional with any questions you may have regarding a medical condition or vaccination schedule. Never disregard professional medical advice or delay seeking it because of something you have read on this website.