First Dengue Vaccine Approved By WHO After Twenty Years of Clinical Studies

On Friday, April 15, 2016, the World Health Organization (WHO) approved Sanofi Pasteur’s Dengvaxia (CYD-TDV), a live recombinant tetravalent vaccine for Dengue fever. The development of a Dengue vaccine is important since there is no cure for the deadly arbovirus, which is spread by Aedes albopictus, as well as the same mosquito that transmits Zika and Chikungunya, the Aedes aegypti.

Pharmaceutical companies have faced several predicaments when developing a vaccine for Dengue since the virus is complex, with four serotypes. Previously, researchers from the United States Food and Drug Administration Center for Biologics Evaluation, along with researchers from the National Institute of Allergy and Infectious Disease created a vaccine which proved 100% successful, however, it only targeted the DEN-2 serotype of the virus. In addition, since human Dengue virus is unique, finding an animal host on which to test the vaccine was a challenge. As a result, only human trials could be used for research, and this proved time-consuming and expensive.

The initial approval for Dengvaxia came after more than 20 years of research from Sanofi Pasteur. During that time period, Sanofi Pasteur conducted 25 clinical trials in 15 countries, worldwide, where 29,000 volunteers were injected with the Dengvaxia vaccine. After Phase III of the clinical studies was completed in 2014, the long-term effects of the vaccine were analyzed, and then published in The New England Journal of Medicine in 2015.

Dengvaxia was first approved by the Federal Commission for the Protection against Sanitary Risks (COFEPRIS) in Mexico on December 9, 2015. The vaccine was approved to be used against all four Dengue serotypes (DEN-1, DEN-2, DEN-3 and DEN-4). Olivier Brandicourt, MD, chief executive officer of Sanofi Pasteur deemed the vaccine a “historic milestone…for the global public health community and, most importantly, for half the world’s population who lives at risk of Dengue.”

The vaccine was later approved in Asia on December 22, 2015, and was granted regulatory approval in Brazil on December 28 of the same year.

Recently, Dengue has been imported to other regions of the world, such as Hawaii. WHO estimates that 390 million people are infected by Dengue virus annually, however, it was noted that Dengue is often misdiagnosed and therefore underreported. An estimated 3.9 billion people worldwide are currently at risk of a Dengue infection. WHO recommends that Dengvaxia be administered as a 3-dose series for individuals between 9 and 45 years of age residing in regions where Dengue is endemic.