Dengue is a viral disease that is mosquito-borne, and it is transmitted by female mosquitoes. Severe symptoms of dengue include DSS or dengue shock syndrome and DHF or dengue hemorrhagic fever. These types of symptoms require hospitalization.

There is an estimate of 400 million people around the world who gets infected by dengue every year. There were no vaccines that were available for the viral disease but recently the U.S Food and Drug Administration approved Dengvaxia which is the first-ever vaccine to prevent dengue disease caused by dengue virus serotypes such as 1,2,3 and 4 in ages 9 to 16 who have previous dengue infection that is laboratory-confirmed.

It is alive, attenuated vaccine that is administered as three separate injections, with the initial dose followed by two additional shots given six and twelve months later.

Anna Abram, FDA deputy commissioner for policy, legislation, and international affairs said,

"Dengue disease is the most common mosquito-borne viral disease in the world and global incidence has increased in recent decades. The FDA is committed to working proactively with our partners at the U.S. Centers for Disease Control and Prevention, as well as international partners, including the World Health Organization, to combat public health threats, including through facilitating the development and availability of medical products to address emerging infectious diseases. While there is no cure for dengue disease, today's approval is an important step toward helping to reduce the impact of this virus in endemic regions of the United States."

Peter Marks, M.D., director of the FDA's Center for Biologics Evaluation and Research said,

"Infection by one type of dengue virus usually provides immunity against that specific serotype, but a subsequent infection by any of the other three serotypes of the virus increases the risk of developing severe dengue disease, which may lead to hospitalization or even death. As the second infection with dengue is often much more severe than the first, the FDA's approval of this vaccine will help protect people previously infected with dengue virus from subsequent development of dengue disease."

Scientists were able to determine the effectiveness of the vaccine and its safety by studying it and giving it to around 35,000 people in dengue-endemic areas including Latin America, Puerto Rico and the Asia Pacific region. The result shows that the vaccine is 76% effective in preventing dengue disease that is laboratory-confirmed in people between 9 and 16 years of age who previously had dengue.

However, the FDA has issued a restricted use of the vaccine as those who were not previously diagnosed with dengue are not advised to receive the vaccine. It is because Dengvaxia will act as their first dengue infection and may lead to severe dengue disease.