A new vaccine for dengue received prequalification from the World Health Organisation (WHO).
QDENGA (TAK-003) is the second dengue vaccine to be prequalified by WHO. Developed by Takeda, it is a live-attenuated vaccine containing weakened versions of the four serotypes of the virus that cause dengue.
WHO recommends the use of TAK-003 in children aged 6-16 years in settings with high dengue burden and transmission intensity.
The vaccine should be administered in a 2-dose schedule with a 3-month interval between doses.
The pre-qualification of TAK-003 is an important step in the expansion of global access to dengue vaccines, as it is now eligible for procurement by UN agencies including UNICEF.
The WHO prequalification list also includes Dengvaxia (CYD-TDV) vaccine against dengue developed by Sanofi Pasteur.
Dengue
• Dengue is a mosquito-borne viral infection, found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.
• It is estimated that there are over 100-400 million cases of dengue worldwide each year and 3.8 billion people living in dengue endemic countries, most of which are in Asia, Africa, and the Americas.
• The largest number of dengue cases reported was in 2023 with the WHO Region of the Americas reporting 4.5 million cases and 2300 deaths.
• Dengue cases are likely to increase and expand geographically due to climate change and urbanisation.
• The virus responsible for causing dengue, is called dengue virus (DENV). It is a virus of the Flaviviridae family and there are four distinct, but closely related, serotypes of the virus that cause dengue (DENV-1, DENV-2, DENV-3 and DENV-4).
• Recovery from infection is believed to provide lifelong immunity against that serotype. Subsequent infections (secondary infection) by other serotypes increase the risk of developing severe dengue.
• Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus. These mosquitoes are also vectors of chikungunya, yellow fever and Zika viruses.
• Aedes aegypti mosquito bites during daylight hours.
• While many DENV infections produce only mild illness, DENV can cause an acute flu-like illness. Occasionally this develops into a potentially lethal complication, called severe dengue.
• Severe dengue is a leading cause of serious illness and death in some Asian and Latin American countries.
Symptoms
• Most people with dengue have mild or no symptoms and will get better in 1–2 weeks. Rarely, dengue can be severe and lead to death.
• If symptoms occur, they usually begin 4–10 days after infection and last for 2–7 days.
Symptoms may include:
i) High fever
ii) Severe headache
iii) Pain behind the eyes
iv) Muscle and joint pains
v) Nausea
vi) Vomiting
vii) Swollen glands
viii) Rash.
• Individuals who are infected for the second time are at greater risk of severe dengue.
• There is no specific treatment for dengue, but the timely diagnosis of dengue cases, identification of warning signs for severe dengue, and appropriate clinical management are key elements of care to prevent the progression to severe dengue and deaths.
• Prevention and control of dengue depend on vector control.
• The first dengue vaccine, Dengvaxia (CYD-TDV) developed by Sanofi Pasteur was licensed in December 2015.