Today, more people living with HIV than ever before have access to life-saving treatment with HIV medicines, which is good for their health. When people living with HIV achieve and maintain viral suppression by taking medication as prescribed, they can stay healthy for many years and greatly reduce their chance of transmitting HIV to their partners. Vaccines historically have been the most effective means to prevent and even eradicate infectious diseases. They safely and cost-effectively prevent illness, disability, and death. Like smallpox and polio vaccines, a preventive HIV vaccine could help save millions of lives. Vaccines made from a live virus may cause you to get the disease the vaccine is supposed to prevent. In general, you should avoid live vaccines, such as chickenpox and smallpox vaccines, and the flu vaccine in the form of a nose spray. Also, avoid close contact with anyone who has had a live vaccine in the past two or three weeks. The measles, mumps, and rubella (MMR) vaccine is the only live vaccine that is sometimes recommended for people with HIV/AIDS.