Latin America. The efficacy per serotype (ST) varied widely, 42.3% for ST2, 50.3% for ST1, 74.0% for ST3, and 77.7% for ST4. The full analysis of data from the phase III Latin American-Caribbean study will be reviewed by external experts before being published in a peer-reviewed scientific journal. Primary results has to be presented at the American Society of Tropical Medicine and Hygiene Annual Meeting, held November 2–6, 2014, in New Orleans. In September 2012, one of the vaccines was reported to not have done well in clinical trials. In late 2015 and early 2016, the first dengue vaccine, Dengvaxia (CYD-TDV) by Sanofi-Pasteur, was registered in several countries for use in individuals 9–45 years of age living in endemic areas. On May 1, 2019, the U.S. Food and Drug Administration announced the approval of Dengvaxia, the first vaccine for the prevention of dengue disease caused by all dengue virus serotypes in people ages 9 through 16 who have laboratory-confirmed previous dengue infection and who live in endemic areas. Dengue is endemic in the U.S. territories of American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands. Drug research There are no approved direct antiviral treatments for Dengue fever. Most antiviral drug research for Dengue infections has focussed on inhibition of the NS2B/NS3 protease or NS5 proteins. Reported protease inhibitor approaches have focussed mainly on targeted covalent inhibitors.' One drug, Balapiravir, a repurposed hepatitis C NS5 polymerase inhibitor progressed to a Phase II clinical trial before being stopped due to lack of efficacy. References External links 3D electron microscopy structures of dengue virus from the EM Data Bank (EMDB) Flaviviruses Dengue fever