The four dengue virus serotypes are mosquito-borne flaviviruses that infect hundreds of millions of individuals reporting flu like symptoms each year in Southeast Asia, western Pacific Islands and Africa.

During secondary infection The virus can cause severe illness, especially when a person who has previously infected with one serotype and then reinfected by a second serotype.

This happens because antibodies from the first infection help the virus replicate during the second infection through a process called antibody dependent enhancement.

The same phenomenon occurs when dengue vaccine induced antibody response weighted towards a single dengue virus serotype.

This study conducted experiments to compare the properties of antibodies against wild-type Dengue viruses and the properties of antibodies produced by a leading vaccine candidate – Dengvaxia – which is used against all four dengue virus serotypes in one formulation.

Though the vaccine stimulated neutralizing antibodies that recognized epitopes common among all serotypes, it did not protect children from dengue.

So, a safe and effective dengue virus vaccine needs to stimulate neutralizing antibodies targeting unique sites on each of the four dengue serotypes. .

Source: Medindia