Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome (AIDS).

HPV is a group of more than 200 related viruses, some of which are spread through vaginal, anal, or oral sex. Sexually transmitted HPV types fall into two groups, low risk and high risk

Hepatitis is an inflammation of the liver. Viruses cause most cases of hepatitis. The type of hepatitis is named for the virus that causes it; hepatitis A, hepatitis B, hepatitis C, hepatitis D and hepatitis E.

The precise scientific term is “indirect protection” or “community immunity.” This is the protection against infection of a susceptible group of individuals