Rotavirus Vaccines — Balancing Intussusception Risks and Health Benefits

In January 2006, the Journal published two landmark articles reporting the safety and efficacy of two different vaccines — RotaTeq (Merck), a pentavalent vaccine (RV5),1 and Rotarix (GlaxoSmithKline), a monovalent vaccine (RV1)2 — to prevent rotavirus, the most common cause of severe childhood diarrhea worldwide and of deaths from diarrhea in low-income countries. Each trial enrolled more than 60,000 infants to determine whether these live oral vaccines caused intussusception, the rare complication that in 1999 forced the withdrawal of the first licensed rotavirus vaccine, RotaShield (Wyeth Lederle), less than a year after it was recommended for routine immunization of U.S. . . .