The battle against antigenic variation
The ability of the immune system to recognize and fight invading pathogens depends on its ability to recognize the antigenic part of the invading organism as foreign. Some organisms are known to have stable antigen and variable antigen. It is the variable antigenic determinants that is the most difficult to handle. This is because of antigenic shift by the organism in an effort to evade the immune system and avoid destruction by the more specific adaptive immune system.
Some organisms like Trypanosome and the orthomyoxviruses, the causative agent of flu are among the organisms known to be able to move from one antigenic type to another. Trypanosome can switch its antigens very quickly leading to parasitaemia and in the process they can weigh down the host immune responds even to the extent that other pathogens can establish and cause infections.
It is said that genetic drift in the flu virus can make it possible for the virus to develop a strain of Avian Flu that can be transmitted to man and from man to man and that will be deadly to man and other animals.
The question is how can we combat these antigenic variations?
Is it possible for man to predict the next possible antigenic switch and develop antibodies that will already be present and ready to fight once the new switch is made? This may be difficult because of the numerous possible shifts available but if the pattern of the switch can be studied and mastered then it may be possible to make prediction of the next possible antigenic switch. The point is that these organisms know that their only hope of survival depends on their ability to switch their variable antigens so it means that as our immune system devices ways to combat these organisms, these organisms’ devices ways to fight back and maintain their existence and persist in the host.
That is the battle against antigenic variation which our immune system must fight to help us survive but I wonder what we can do to assist our immune system in the battle for survival.