I need a medication that stops drop in immunity in order not to develop herpes simplex infection frequently..

Oral Herpes: If you are an otherwise healthy 21 year old male, there is nothing you need to do about "drop in immunity". If you know that you have a disease process or take medications that suppress or compromise your immunity, you need to talk to your doctor; otherwise, you need to be on antiviral meds such as Acyclovir • Famciclovir • Valacyclovir especially when you have active eruptions.