Pathogen virus antigens
The chemistry of the outer shell is usually lipoprotein and in some viruses a glycoprotein. The shell often contains specific antigens such as erythrocyte agglutinin factor.
For humans and animals, microorganisms and their toxins are antigens. Each microbial strain is composed of many complex substances and has different antigenic properties, so each microbial strain has many antigens.
Viral antigens are divided into two categories: soluble antigens and antigens that are part of the viral particle structure.
These are antigens obtained from cell cultures infected with viruses after the virus and cell components have been eliminated. These antigens may be viral enzymes, structural components that the virus has over-synthesized during replication. These antigens have little practical significance.
Viral particle antigens
All viruses have two basic components, nucleic acid, and a capsid. Some viruses also have an envelope.
An antigenic complex is made up of nucleic acids and proteins. In influenza viruses, ribonucleoproteins are type-specific antigens.
It is the most important and powerful antigen of the virus because the capsid contains most of the viral protein. It can be a separate antigen or bind to a nucleoprotein to form a complex antigen. The protein coat causes the body to neutralize antibodies that ensure specific immunity against the virus. This antigen plays an important role in the classification of enveloped viruses.
The chemistry of the outer shell is usually lipoprotein and in some viruses a glycoprotein. On the shell often contains specific antigens such as erythrocyte agglutination factor or neuraminidase, erythrocyte agglutinin antigens are useful for virus detection and diagnosis.