Will Dengue patients become immune to dengue after suffering from it once?
Dengue is one of the most common vector borne disease. Once infected with dengue fever will result in formation of antibodies for life time. But for dengue there is flip side.
Dengue virus have 4 sub types (DEN1,DEN2,DEN3 and DEN4) these are having 60 to 80% genetic similarity to each other. When a person is infected by dengue, immune system will be ready with antibodies for that sub-type.
When the same person is infected with another sub type of dengue, immune system will produce defense as if it is the previous sub-type. More macrophages will be produced to bind the intruder, but the virus will not be nutralised. It will continue the attack. Immune system will be tricked due to the similarity in the virus.
Hence the 2nd attack may be severe than the first one.