Although some data have suggested a possible increased risk of intussusception (when a portion of the small or large intestine slides forward into itself, like a telescope) after administration of the pentavalent rotavirus vaccine in infants, an analysis that included almost 800,000 doses administered to U.S. infants found no increased risk of this condition following vaccination, according to a study in the February 8 issue of JAMA.
"In 1999, the rhesus tetravalent rotavirus vaccine (RRV, Rotashield) was withdrawn from the U.S. market due to a significantly increased risk of intussusception following vaccination," according to background information in the article. "Since then, 2 vaccines to prevent rotavirus infection have been licensed for use in the United States: a pentavalent rotavirus vaccine (RV5, RotaTeq) in 2006 and a monovalent rotavirus vaccine (RV1, Rotarix) in 2008." Large prelicensure trials were conducted because of the prior association between RRV and intussusception, with no increased risk observed. "However, 2 recent international postlicensure evaluations [conducted in Australia, Mexico and Brazil] have observed an increased risk of intussusception in the first week after administration of the first dose of rotavirus vaccines."
Irene M. Shui, Sc.D., of Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, and colleagues reexamined intussusception risk associated with rotavirus vaccination, with a specific focus on the 1- to 7-day risk window after administration of the first dose. The study included infants 4 to 34 weeks of age, enrolled in the Vaccine Safety Datalink (VSD) who received RV5 from May 2006 - February 2010. Among the analyses the researchers performed was a comparison of the rates of intussusception in infants who had received RV5 with the rates of intussusception in infants who received other recommended vaccines without RV5 during the same period. The authors also included data on the expected number of intussusception visits based on background rates assessed prior to U.S. licensure of the RV5 (2001-2005).