By Dr. Brian McDonough

PHILADELPHIA (CBS) – Today is World AIDS Day.

There is plenty we can celebrate because people are living longer and are able to do quite well living with HIV. That’s because there are medications out there that can make a difference.

There are still many concerns, however.

1.2 million people in the United States are living with HIV. An estimated one in eight people don’t know they are infected, which means they aren’t getting treatment and run the risk of spreading to others.

Since 1981, of the 1.2 million people in the United States diagnosed with AIDS, 658,000 have died.