Vaccine (IMAGE) University of Missouri-Columbia Caption Clinical trials are under way for an immunodeficiency virus (HIV) infection, the cause of AIDS. Programs of population-wide vaccinations resulted in the eradication of smallpox; elimination of polio in the Americas; and control of measles, rubella, tetanus, diphtheria and other infectious diseases in the US and other parts of the world. Credit Jim Gathany, CDC Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.