Getting and keeping an undetectable viral load* is the best thing people with HIV can do to stay healthy. Another benefit of reducing the amount of virus in the body is that it helps prevent transmission to others through sex or syringe sharing, and from mother to child during pregnancy, birth, and breastfeeding. This is sometimes referred to as treatment as prevention.
* A person with HIV who takes HIV medicine as prescribed and gets and stays virally suppressed or undetectable can stay healthy and has effectively no risk of sexually transmitting HIV to HIV-negative partners.