As a swine flu virus appears to make its way across the world, so has misinformation and confusion about what the virus is and what sort of threat it poses, particularly for people with weakened immune systems or some people living with HIV. To help us fill in that knowledge gap, we've asked Dr. Joel Gallant for some insights. Dr. Gallant is a professor of medicine and epidemiology in the Division of Infectious Diseases at the Johns Hopkins University School of Medicine and he happens to be one of the leading HIV specialists in the United States.