Three Dengue Vaccines — What Now?

In 2019, the four serotypes of the mosquito-borne dengue virus (DENV) caused an estimated 56 million cases of disease and 5000 to 40,000 deaths in a global swath of tropical and near-tropical countries, defying control and motivating the development of vaccines.1 Outcomes of clinical trials of dengue vaccines are necessarily governed by the biologic and immunologic behavior of DENV in humans. Initial infection with any DENV serotype in persons who have not previously been infected with DENV typically results in at most mild-to-moderate febrile illnesses of short duration. These initial infections provide lifelong protection against reinfection with the same immunologic . . .