How does the Herpes Vaccine Work?

Herpes is a virus that can cause painful blisters and sores. There are several types of herpes and all types can be spread from one person to another. The herpes simplex virus causes both oral and genital herpes and the herpes zoster virus causes chicken pox and shingles. There is no cure for herpes and though medications can alleviate the symptoms of the recurring infections caused by this virus, until recently there was also no way to prevent the virus from spreading if contact was made with someone who was infected. However, researchers have been developing a herpes vaccine to prevent the spread of herpes.

Several herpes vaccines are in the works, as each type of herpes virus demands its own herpes vaccine. Genital herpes, which is caused by the herpes simplex two virus, affects approximately 55 million Americans, and an effective vaccine for this type is in especially high demand. To understand how a herpes vaccine works, one must first understand how herpes overtakes the body’s defense mechanisms.

First, the herpes simplex virus infects a cell. That cell, in turn, sends out a signal to alert other cells of impending danger. The cells receiving the signal then revert to an anti-viral status as a means of protection, essentially creating a shield to ward off harm. However, the herpes virus produces a protein called ICPO that gets tricky and causes the infected cells to destroy their own shields. This then allows the herpes virus to take over, multiply, then jump over to new cells and trick them as well. Mass chaos ensues, and the herpes virus finds a home in a large group of cells.

So, to allay the effects of this deceptive invasion, scientists are creating a herpes vaccine that removes the genetic instructions for producing the protein ICPO. Without these instructions, the virus has no ICPO with which to trick the cells, so though the rest of the virus remains intact, it is rendered impotent and unable to cause harm. Weakening a virus in this manner creates what is known as an “attenuated” virus. Other vaccines that use this approach are measles, mumps, rubella, polio and yellow fever.

Herpes zoster has a vaccine as well. This herpes vaccine is given to prevent both shingles and chicken pox. Though slightly different than the vaccine in the works for herpes simplex, the zoster vaccine also works by injecting weakened versions of the virus. The shingles vaccine and the chicken pox vaccine both contain a strain of weakened varicella zoster virus.