Like polio, rubella had been at one time a common and serious childhood disease. Today, most U.S. children are routinely vaccinated against polio, rubella, and 14 other diseases—including one for which Dr. Offit helped develop the vaccine. Dr. Offit teamed up with Dr. Plotkin and Dr. H. Fred Clark, a research professor in Philadelphia. The three are credited with creating a vaccine to prevent a life-threatening disease called rotavirus. The rotavirus can cause high fever, vomiting, and severe diarrhea, which can be devastating for young children. When Dr. Offit started his research, about 75,000 children—most under the age of 5— were hospitalized with rotavirus each year. Today, the number has dropped dramatically because the vaccine is so effective. Dr. Offit and his colleagues worked for 26 years on the vaccine before it was available to children. Ten of those years were spent learning how the rotavirus makes children sick, Dr. Offit says. Then they devoted 16 years to developing the vaccine. Other people helped as well to make sure the vaccine was safe and effective. There was no guarantee the long process would end with success. “When you’re just starting out, you don’t think you’re going to be able” to make a vaccine, Dr. Offit says. But he never considered giving up. In fact, he says, “It was fun. ... I was in Paul Offit Educating people about how vaccines save lives When he was 5 years old, Dr. Paul Offit had an operation on his right foot. While recovering in a hospital ward, he met other children who were suffering from a disease called polio. “They were vulner- able and helpless,” Dr. Offit recalls. Polio was a common illness back then, and it could para- lyze and even kill children. In those days, hospitals were lonely places for children. “There were no iPads or play therapy or TVs,” Dr. Offit says. “Their families could only visit for a short time—one hour, once a week.” That hospital experience left a lasting impression on him. Fast-forward many years: Dr. Offit grew up, studied medicine, and became a pediatrician. When he was a young doctor, he met Dr. Stanley Plotkin, a scientist who had developed a vaccine against the rubella virus. “That really impressed me,” Dr. Offit says. In most people, rubella causes a mild illness. But if a woman is infected when she is pregnant, it can cause birth defects in her unborn baby. 22