What is it?

Dengue Fever is caused by dengue virus and is spread by mosquitos (specifically Aedes aegypti, which is the same type of mosquito that spreads Zika, chikungunya, and yellow fever). There are four different serotypes of dengue, and people can get infected multiple times. 

Dengue can cause a wide range of symptoms. Sometimes dengue causes almost no symptoms but it can also cause severe disease (severe bleeding and organ failure), which can be deadly.

The dengue vaccine (Dengvaxia) is recommended for people 9-16 years old who have previously had dengue (confirmed with a test). Previous infectious is part of the recommendation because people who are vaccinated who have not had dengue before are more likely to have severe infection and require hospitalization. This is due to antibody-dependent enhancement (to learn more, click here). 

Vaccine Information:

Active Ingredients:

A live, attenuated version of yellow fever virus with certain genetic sequences replaced with ones from dengue virus

Inctive Ingredients:

Salts: help maintain the stability and pH of the vaccine



  • Attenuated: The pathogen is weakened but not completely inactivated. Attenuated pathogens are too weak to cause disease in almost all people. 

  • Bacteria: A type of single-celled organism. Some can cause disease, but many are harmless and some actually benefit humans by living in the intestines and helping with digestion 

  • Bacterium: The singular of bacteria (one bacterium, two bacteria)

  • Meningitis: inflammation of the lining of the brain and spinal cord

  • Serotype: a group of strains within a species that share a particular type of surface structure. 

  • Strain: Within a particular species there can be a lot of genetic diversity. A strain refers to one member of that species. 

  • Vaccine Efficacy: How much a vaccine reduces your chance of getting a disease