Dengue: Status of current and under‐development vaccines

Abstract

Dengue is an emerging mosquito-borne viral infection with increasing reports of outbreaks. The clinical picture ranges from a benign febrile illness through to severe and potentially fatal manifestations. No specific anti-viral treatment exists, and therapy only consists of supportive care. During the last three decades, several attempts to develop an effective vaccine have been made. The first dengue vaccine to obtain licensure was Dengvaxia®, which was authorized in 2015 and is currently available in over twenty countries. Its use has been approved with strict limitations regarding age and serostatus of the recipients, highlighting the necessity for a more safe and efficacious vaccine. At present several vaccine candidates are undergoing clinical and pre-clinical trials. The most advanced candidates are TDV and TDV 003/005, two live-attenuated vaccines, but another 15 vaccines are under development, introducing novel immunization strategies to the traditional dengue vaccine scenario. This work reviews the current research status on dengue vaccines.

COVID-19: Famotidine, Histamine, Mast Cells, and Mechanisms

“…This model is consistent with the histopathologic ndings seen at surgery, autopsies, and is supported by clinical pharmacologic ndings suggesting potential bene ts of histamine H2 receptor blockade using famotidine. This model is also supported by the signi cant overlap in the clinical signs and symptoms of the initial phase of COVID-19 disease and those of mast cell activation syndrome (MCAS) [91][92][93][94] as well similarities to Dengue hemorrhagic fever and shock syndrome (including T cell depletion) during the later phase of COVID-19 85,95,96 . The cardiac events, stroke, and related outcomes associated with COVID-19 also appear consistent with the Kounis syndrome [97][98][99] .…”

Zika virus infection enhances future risk of severe dengue disease

“…ZIKV spread across the Pacific and Americas in 2013 to 2017 and caused rare but devastating clinical outcomes, including congenital microcephaly and Guillain-Barré syndrome in adults (2,4). Vaccines against both dengue and Zika are undergoing clinical evaluation (4,5). However, the only licensed dengue vaccine, Dengvaxia, increases risk of severe dengue in previously DENV-naïve individuals (6).…”

COVID-19: Famotidine, Histamine, Mast Cells, and Mechanisms

“…This model is consistent with the histopathologic ndings seen at surgery, autopsies, and is supported by clinical pharmacologic ndings suggesting potential bene ts of histamine H2 receptor blockade using famotidine. This model is also supported by the signi cant overlap in the clinical signs and symptoms of the initial phase of COVID-19 disease and those of mast cell activation syndrome (MCAS)[91][92][93][94] as well similarities to Dengue hemorrhagic fever and shock syndrome (including T cell depletion) during the later phase of COVID-1985,95,96 . The cardiac events, stroke, and related outcomes associated with COVID-19 also appear consistent with the Kounis syndrome97-99 .…”