Intussusception is a rare type of bowel blockage that occurs when a part of the bowel telescopes down into another segment. Sometimes, the bowel blockage self-corrects, but it can also require surgery, and in rare cases lead to death. The number of reported cases is approximately what would be expected based on the natural rate of occurrence of intussusception, regardless of vaccination. However, given that under-reporting of cases occurs in every surveillance system, this information is concerning. In addition, post-licensure studies in Northern California, Minnesota and South Carolina also support a link between rotavirus vaccine and increased risk of intussusception in the first 3 weeks following vaccination.
Risk is highest in the first week after vaccination.
Because the number of cases in the above studies is small, CDC is conducting a large-scale national study to determine if there is an association between rotavirus vaccine and intussusception. NYC DOH's Bureau of Immunization and Communicable Diseases is participating in this study. Results should be available in October. Until the results of the large-scale study are available, rotavirus vaccine should not be administered to any child. This includes children who have already begun the series and only need one or two more doses to finish the series.