Exploring Bioethics - NIH Office of Science Education - National ...

Station 1: Vaccine-Preventable DiseasesChickenpox (Varicella)Child with chickenpox.Photo: Courtesy CDCBefore the chickenpox vaccine was licensed in 1995, almost allpeople in the United States had suffered from chickenpox byadulthood. Each year, the virus caused an estimated 4 million casesof chickenpox, 11,000 hospitalizations, and 100 to 150 deaths.A highly contagious disease, chickenpox is usually mild but canbe severe in some people. Infants, adolescents, adults, pregnantwomen, and people with weak immune systems are at particularrisk for serious complications. Since the vaccine was introduced,the number of hospitalizations and deaths from chickenpox hasdeclined more than 90 percent.Hepatitis BCopyright © 2009 Education Development Center, Inc. Exploring Bioethics.Permission granted for classroom use.Transmission electron micrographof hepatitis B virus particles.esy CDC/almerPhot o: CourtDr . Erskine PThe hepatitis B virus (HBV) attacks the liver. Chronic (long-lasting)HBV infection increases a person’s risk of liver disease, cirrhosis(scarring) of the liver, liver cancer, liver failure, and death.In 1981, the year the HBV vaccine was introduced, about 21,000new cases of the severe (acute), symptomatic form of HBV infectionwere reported in the United States. Many cases were not reported,so the actual number may have been as high as 70,000 per year. In2006, about 4,700 new cases of acute hepatitis B were reported, adecline of about 75 percent of reported cases since 1981.About 12.5 million people in the United States have been infectedwith HBV at some point in their lives, and about 1.25 millionhave chronic infection. Approximately 25 percent of childrenwho have chronic HBV infection are likely to die of related liverdisease as adults. About 5,000 people die each year from HBVrelatedliver disease.Master 2.3 (Page 1 of 4)