The plot of Will Smith's I Am Legend:

The film opens in 2009 with a televised news broadcast with Dr. Alice Krippin (Emma Thompson) who has created a cure for cancer (100% cure rate) by altering the measles virus.

In a post-apocalyptic 2012, U.S. Army virologist, Lieutenant Colonel Robert Neville (Will Smith) is left as the last healthy human in New York City and possibly the entire world. A series of flashbacks and recorded news programs reveal that the genetically re-engineered measles virus (referred to as K.V. or Krippen Virus) mutated into a lethal airborne strain that spread worldwide and killed 5.4 billion people, 90% of humanity. Only 12 million possessed a natural immunity. The remaining 588 million, after initially exhibiting symptoms resembling rabies, degenerated into primal, aggressive beings referred to as "Darkseekers" (the DVD subtitles refer to them as hemocytes) who have a painful intolerance to UV radiation, forcing them to hide in buildings and other dark places during the day. The "Darkseekers" exhibit superhuman speed, agility, and strength. They also retain some problem-solving intelligence and the capacity to organize. The immune humans were killed by the infected in a civil war that took place between 2009 and 2012, or committed suicide.

What scientists are now doing to find a cure for AIDS:

The approach taken in the current study was divided into two phases. In the first phase, the research team created antibody-like proteins (called immunoadhesins) that were specifically designed to bind to SIV and block it from infecting cells. Once proven to work against SIV in the laboratory, DNA representing SIV-specific immunoadhesins was engineered into a carrier virus designed to deliver the DNA to monkeys. The researchers chose adeno-associated virus (AAV) as the carrier virus because it is a very effective way to insert DNA into the cells of a monkey or human.

It always makes me squeamish when they start engineering viruses or genetically altering existing ones. I really wish they'd just make a big vitamin or something for everyone and be done with it.