In 2006, the United States introduced a vaccine for rotavirus, the illness that causes diarrhea and can lead to dehydration, fever and, in severe cases, death. The Centers for Disease Control and Prevention reports that almost all children had one bout of rotavirus by the time they were 5.
The rotavirus vaccine has dramatically reduced the number of hospital visits for the illness domestically. However, that's not the case in developing countries. The effectiveness of the vaccine is markedly less in some countries than it is here.
Vermont Edition spoke to Ross Colgate, a research analyst at the UVM College of Medicine's Vaccine Testing Center, about why the oral vaccine for rotavirus is effective in the United States and much less effective in some developing countries.