Antigenic variation

Antigenic variation

Antigenic variation is the process by which an infectious organism alters its surface proteins in order to evade a host immune response. This change in antigenic profile may occur as the pathogen passes through a host population (also called "antigenic diversity") or may take place in the originally infected host. The strategy is particularly important for organisms that target long-lived hosts, repeatedly infect a single host, and are easily transmitted. Pathogens that express these characteristics and undergo antigenic variation have a selective advantage over their more genetically stable counterparts.

Antigenic variation can occur through three broadly defined genetic processes: gene mutation, recombination, and switching. In all cases, antigenic variation results in pathogens that are immunologically distinct from the parental strains.

One possible consequence of antigenic variation is antigenic escape.


* Barbour AG, Dai Q, Restrepo BI, Stoenner HG, Frank SA., "Pathogen escape from host immunity by a genome program for antigenic variation", Proc Natl Acad Sci U S A. 2006 Nov 13;
* Barbour AG, Restrepo BI., "Antigenic variation in vector-borne pathogens."Emerg Infect Dis. 2000 Sep-Oct;6(5):449-57. Review.

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