Dengue viruses (DENV) are transmitted by Aedes mosquitoes. There are 4 serotypes of dengue, and all 4 appear to be circulating in most endemic countries. Clinical disease varies from a mild febrile illness to severe disease. The most common clinical presentation includes sudden onset of fever, headache, retro-orbital pain, myalgia and arthralgia, abdominal pain, and nausea.
Severe disease includes plasma leakage, shock, respiratory distress, severe bleeding, and organ failure. While severe dengue can occur with a primary infection, a second infection with a different DENV increases the risk of severe dengue. A small increased risk of severe dengue occurs when dengue infection occurs after vaccination in those with no evidence of previous dengue infection. It is felt that the vaccine serves as a primary infection that increases the risk of severe dengue with subsequent infections. This is the reason that the vaccine is recommended only for those with a documented previous dengue infection.
At its June 2021 meeting, the ACIP recommended 3-doses of Dengvaxia, administered at 0, 6, and 12 months, for individuals 9 to 16 years of age who have laboratory confirmation of previous dengue infection and live in endemic areas.12 These areas include the territories and affiliated states of Puerto Rico, American Samoa, US Virgin Islands, Federated States of Micronesia, Republic of Marshall Islands, and the Republic of Palau. Puerto Rico accounts for 85% of the population of these areas and 95% of reported dengue cases.12The reason for the delay between FDA approval and the ACIP recommendation was the need to wait for a readily available, accurate laboratory test to confirm previous dengue infection, which is now available. There are other dengue vaccines in development including 2 live-attenuated, tetravalent vaccine candidates in Phase 3 trials.