Final answer:
A person infected with the herpes simplex virus will remain infected for a lifetime due to the virus' ability to establish a latent infection in the nervous tissue and periodically reactivate.
Step-by-step explanation:
Once an individual is infected with the herpes simplex virus (HSV), the virus remains in their body for a lifetime. This is because HSV can establish a latent infection in nervous tissue, where it goes into a dormant state and does not produce significant amounts of viral proteins.
The immune system, therefore, has nothing to act against, causing a decline in immunity towards the virus. During periods of stress or immune suppression, HSV can reactivate and cause lesions or cold sores, known as a lytic replication cycle.
Even though these outbreaks resolve in a few days or weeks, the virus persists latently in the body. This pattern of latency and intermittent reactivation is also observed with other herpesviruses, such as the varicella-zoster virus, which can result in chickenpox during initial infection and shingles upon reactivation later in life.