Viral Antigens: http://www.creative-diagnostics.com/Viral-Antigens.htm
A virus antigen is a toxin or other substance given off by a virus which causes an
immune response in its host. A viral protein is an antigen specified by the viral
genome that can be detected by a specific immunological response.
Viruses are complexes consisting of protein and an RNA or DNA genome. They lack
both cellular structure and independent metabolic processes. They replicate solely by
exploiting living cells based on the information in the viral genome.
A mature virus particle is also known as a virion. You can find more information
about Viral Antigens by the link below: