Unless a dengue vaccine protects against all four different virus types, or serotypes, developing a viable vaccine against dengue virus is difficult.
The University of North Carolina health care investigated samples from children enrolled in a dengue vaccine trial to identify the specific kinds of antibody responses that correlate with protection against dengue virus disease to overcome this difficulty.
The published study in the Journal of Clinical Investigation discovers that a small subpopulation of antibodies binding to unique sites on each serotype are linked to protection. This information is important for vaccine developers to consider when creating a dengue vaccine.
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. .