Any virus is nothing more than a bit of nucleic acid enclosed in a protein package. The outer packet is called capsid. The internal nucleic acid is the genome of the virus. It will be either DNA or RNA—viruses that coexist have not yet been discovered. Some viruses have another layer outside the capsid, called the envelope.

dengue

It is composed of phospholipids, proteins and glycoproteins etc. They are the materials of cell membrane. So viruses are not cells. The envelope is essentially a stolen part of the cell in which the virus has previously replicated. Dengue virus is a type of RNA virus, that is, there is only RNA inside the capsid.

Not all dengue viruses are alike, just as all humans are members of the same species. Variations in RNA signals in their genomes lead to differences in protein structure. Because of this, there are subtle but significant differences in how the body's immune system reacts to different strains of the same virus.

Based on these differences, four serotypes of dengue virus DENV1, DENV2, DENV3 and DENV4 have been identified. Multiple strains belonging to each serotype have been identified based on more subtle differences. But in this discussion, it will work even if you don't know that much. Like all other organisms, viruses are adapting to changing environments and conditions. A fifth serotype of dengue, DENV5, has recently been discovered. We have very insufficient information about it.