Dengue Vaccine Implementation in Countries Like The US Might Worsen Viral Disease

Dengue is one of the leading viral diseases that cause serious mortality around the world. The virus is transmitted by mosquitos which created major outbreaks in tropical and subtropical regions. For years, scientists and epidemiologists of tropical medicine were focused on developing vaccines for the 4 known serotypes of the virus. However, a study claims that dengue vaccines are increasing the virulence of the virus thus worsening the virus.

Scientists studied a data of over 30,000 dengue vaccine trial in 10 countries. The study discovered that the vaccine reduced the illness and hospitalization by 30 percent only to areas with high dengue transmission and high reported outbreaks. On the other hand, in areas with low incidence of dengue, patients tend to exhibit more severe symptoms.

The researchers were particularly concerned about the increasing virulence of dengue in areas with low prevalence like in the United States. In a report by United Press International, research co-lead author Dr. Isabel Rodriguez-Barraquer said: "In vaccines, you hope for more than 30 percent success, but it's the only vaccine available right now to slow dengue. If this vaccine is used correctly, many people could be spared illness and hospitalization from dengue. But we should make sure we only use it in places where our data suggest it will do more good than harm."

Because of their findings, WHO released a recommendation that the use of vaccine should be implemented in countries with high dengue transmission.

The research's co-author Derek Cummings of the University of Florida elaborated in a university press release "We should be careful in considering where and how to use this vaccine as there is still uncertainty about its impact,"

According to CDC, 2.5 billion people or 4 of every 10 people is at risk of acquiring the viral disease.  In the US, most reported cases were acquired by travelers  and immigrants from countries with high prevalence. If this situation continues, we might see even worse than what dengue is now.