Stock Market Update; Viruses

Guest host Neil Cavuto and financial consultants from BusinessWeek, The New York Times, and Bloomberg News analyze today's staggering loss and overall volatility in the stock market. Guest host Dr. Harold Varmus speaks with Dr. Eckard Wimmer and Dr. Peter Kim about their respective work with the polio and AIDS viruses, which is influencing potential public policies on the threat of bioterrorism and the HIV epidemic.