A health worker collects a blood sample from a woman who has had dengue fever (file photo).
The World Health Organization (WHO) said today that the quadrivalent live attenuated dengue vaccine (TAK-003), developed by Takeda Pharmaceuticals, became the second dengue vaccine to be prequalified by the organization.
WHO notes that dengue fever poses a significant public health burden in endemic countries. The Takeda dengue vaccine has been shown to be effective against all four viral serotypes in children (aged 4-16 years) who are seropositive at the start of the epidemic and against virus serotypes 1 and 2 in children who are seronegative at the onset.
WHO recommends the vaccine for children aged 6 to 16 years. For this age group, the vaccine should be given approximately 1-2 years before the peak of dengue-related hospitalizations and should be given in two doses, 3 months apart.
Rogerio Gaspar, WHO's Director of Regulatory and Prequalification, said the prequalification of TAK-003 is an important step in expanding the use of dengue vaccine globally, meaning it is eligible for procurement by UN agencies such as UNICEF and PAHO.
He noted that to date, only two dengue vaccines have been prequalified, and he expects more vaccine developers to come and be evaluated to ensure that the vaccines reach all communities that need them.
Previously, the CYD-TDV dengue vaccine developed by Sanofi Pasteur has entered the WHO's list of prequalified vaccines.
About dengue fever
The dengue virus is transmitted to humans through the bite of an infected mosquito and is commonly found in tropical and subtropical climate regions of the world, mainly in urban and semi-urban areas. The main vector of transmission of the disease is Aedes aegypti mosquito, followed by Aedes albopictus mosquitoes, although in some regions such as Europe and North America, Aedes albopictus is more widely distributed.
There are four serotypes of dengue virus. Infection with one serotype confers long-term immunity to the same serotype and only temporary immunity to other serotypes, and successive infection with different serotypes increases the risk of severe dengue. Cases of dengue fever are usually asymptomatic or cause mild febrile illness. However, some cases progress to severe dengue fever, which may lead to shock, severe bleeding, or severe organ damage. This stage usually begins after the fever has subsided, preceded by some warning signs such as severe abdominal pain, persistent vomiting, bleeding gums, fluid buildup, lethargy or irritability, and an enlarged liver.
There is no specific treatment for dengue, but timely diagnosis of dengue cases, recognition of warning signs of severe dengue, and appropriate clinical management are key elements of care to prevent the progression to severe dengue and death.
