Dengue fever vaccine moves forward

Photograph by Donaldo Zuluaga. This container is used to store vector mosquitoes of tropical diseases such as dengue fever and malaria. PECET director claims that as soon as dengue fever vaccine is available Colombia would have full access to vaccine because of its contribution to research.

Researchers at University of Antioquia found dengue vaccine safe for humans.

Clinical trials of vaccine against dengue fever in Antioquia show promising results.

"This is the safest vaccine ever tested" says Doctor Ivan Dario Velez, director of the Program for the Study and Control of Tropical Diseases – PECET –.

Dengue vaccine trials were conducted on volunteers living in San Nicolas valley, eastern Antioquia, where the mosquito that transmits the disease is not found since it usually inhabits tropical areas below 1.800 meters above sea level. However, the major mosquito vector, aedes aegypti, has been found in locations above this altitude. Experts say that global warming also contributes to expansion of mosquito habitat.

Vaccine manufacturer Inviragen in partnership with researchers at University of Wisconsin are planning to conduct clinical trials of Denvax in areas where the mosquito is present.

New clinical trials are expected to be conducted in Medellin and the northern town of Bello since dengue fever in these cities killed 14 last year after an epidemic encompassing 17,623 cases.


Promising results
According to Dr. Velez this study caught the eye of researchers around the world as dengue fever is increasingly spreading in countries with no previous outbreaks of this disease. “The international scientific shows great interest in dengue vaccine since this disease is a major public health problem that knows no boundaries”, he says.

However PECET director is cautious and says that although dengue vaccine development is moving forward more work remains to be done.

“Now we have a more effective vaccine but we cannot claim victory yet as we don't mean to raise false expectations. Our work has yielded remarkable results so far” stresses Dr. Velez.

Pharmaceutical companies Glaxo and Sanofi Pasteur are also testing vaccines against the disease that killed 174 people in 2010. Sanofi’s vaccine is currently under test in five Latin American countries including Colombia.


Advances
PECET researchers stress that unlike above-mentioned vaccines Inviragen’s Denvax is a two-dose vaccine taken in an interval of 90 days. Other vaccines require an additional dose.

How does vaccine work?
Serotypes causing dengue fever are genetically modified and incorporated into the vaccine.

“Viruses on four serotypes are modified in laboratories in order to get immunization rather than causing the disease”, explains clinical trial coordinator Liliana López.

PECET director also stresses that vaccine creates antibodies that protect recipients against four types of dengue fever.