Atypical dengue fever in a partially vaccinated patient: a case report

Dengue fever is an acute, systemic, and debilitating febrile illness that poses a significant global public health threat. Vaccination is important in combating the virus in highly prevalent countries, as it reduces the risk of symptomatic infection, hospitalizations, morbidity, and mortality. We report a unique case of atypical dengue fever in a previously healthy 42-year-old Brazilian woman. She developed dengue without the characteristic fever or elevated inflammatory markers 15 days after her initial TAK-003 (Q-denga) vaccine dose, setting her case apart from typical manifestations. 'Whether the mildness of the case was due to the vaccine's protective effect or if it was caused by the vaccine virus itself, as genetic sequencing of DENV-2 was not possible, is unclear. In regions where the vaccine is being introduced, atypical cases, particularly those without fever, require thorough investigation, so dengue can be excluded.