Is PrEP a vaccine？

No. PrEP does not work the same way as a vaccine. A vaccine teaches your body to fight off infection for several years. For PrEP, you take a pill every day by mouth. The pill that was shown to be safe and to help block HIV infection is called “Truvada” (pronounced tru vá duh). Truvada is a combination of two drugs (tenofovir and emtricitabine). If you take PrEP daily, the presence of the medicine in your bloodstream can often stop HIV from taking hold and spreading in your body. If you do not take PrEP every day, there may not be enough medicine in your bloodstream to block the virus.