Virus capsid is made up of

A virus capsid is made up of Protein.
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric structural subunits made of proteins called protomers.
The majority of the viruses have capsids with helical or icosahedral structure. Once the virus has infected a cell and begins replicating itself, new capsid subunits are synthesized using the protein biosynthesis mechanism of the cell.
In some viruses, including those with helical capsids and especially those with RNA genomes, the capsid proteins co-assemble with their genomes.