immunodeficiency
An antigenic variation is the mechanism by which an infectious organism changes its surface proteins in favour of circumventing a host immune response.
When a parasite hides from the immune system of a host. e.g. in the liver cells
Antigenic variation is a mechanism used by certain pathogens, such as viruses and bacteria, to change their surface antigens, making it difficult for the immune system to recognize and mount an effective response against them. This allows the pathogen to evade immune detection and establish persistent infections in the host.
Small molecules that bind with self-proteins to produce antigenic substances are called happens. The unique area that a lymphocyte recognizes and binds to an antigenic determinant.
Since immunogenic means 'Capable of inducing an immune response; antigenic.' I would suggest that nonimmunogenic would mean that an immune response would not be induced.
The basic determining feature of antigenic specificity is the unique structure of antigenic epitopes, which are the specific regions on an antigen recognized by antibodies or T cell receptors. These epitopes interact with corresponding binding sites on antibodies or T cell receptors, leading to the immune response against the antigen.
For example in regards to influenza viruses, an antigenic site is the area on the protein spike protruding from their lipid bilayer that carries the receptor binding sites. This is supposed to trigger an immune response when your body detects these sites by binding antibodies to them.
The Phase Variation is the reversible ability of some bacteria to turn an and off the expression of genes coding for the surface antigens . While the Antigenic Variation is the modification of the gene for an expressed surface antigen by genetic recombination with one of many variable unexpressed DNA sequences. In this manner , the expressed surface antigen can assume many different antigenic structures
These virus have changed their recognition sequence either via mutation or antigenic drift and are able to escape cytotoxic T lymphocytes of the immune response
An allergic reaction i believe.
The immunologist studied how the body's immune system responds to a new vaccine.
The genome of viruses can mutate over time through a variety of mechanisms. Some viruses are more prone to these mutations than others. When the genome changes, this changes the proteins that are expressed by the virus, included the proteins that are present on the surface of the virus. These proteins are the antigens that are recognised by the host immune system and which trigger the immune response. Antigenic drift is when the genome of the virus mutates thus changing the antigens expressed by the virus. This means that an individual immunized against a virus may not be protected if the virus undergoes antigenic drift as the proteins present of the surface of the virus are not the same as the virus against which the individual was immunized.