As bacteria become increasingly resistant to antibiotics scientists have begun a desperate search for alternatives to the drugs. In one approach, they are trying to harness viruses that naturally evolved to prey on harmful bacteria and to use them as weapons for staving off intruders. This is not a new idea but rather is a revival of an ancient remedy using bacteria-eating viruses--bacteriophages, or just phage for short--to kill bacteria. Several start-up companies already have plans to test the phages in humans, but while they have a lot of great potential there are risks involved. The viruses can multiply quickly in a host and in some cases may produce toxic chemicals. And, if the phage is allowed to replicate without being restricted, it could potentially kill its host.
New York Times May 18, 2004