MD Lingo

Medicine as you will know it

Links between New Generation Rotavirus Vaccination and Intussusception

By Morolake Amole

The subject of immunization, especially in children, has been the topic of great discussion amongst parents and medical professionals. Many parents are appropriately concerned about the safety of vaccinating children. In the early 1900’s, polio was a worldwide epidemic that ravaged many parts of the United States. The outcomes of Polio infection were catastrophic, leaving many dead or permanently paralyzed. This reflection on one of the scariest times in American history, underscores the importance of the polio vaccine, which served as nothing short of a medical miracle. Even with the memory of how vaccinations have contributed to survival, the shear idea of injecting children with a killed version of a potentially deadly virus rightfully sends many parents into a state of fear. Of course, vaccination, like any medical procedure, is not without its risks. One recent study, published in the New England Journal of Medicine discusses the link between the Rotavirus vaccine and the development of Intussusception, an intestinal disorder, in infants.

Rotavirus is a self-limiting viral infection that causes gastroenteritis (or inflammation of the digestive tract), most often in young children aged 6-36 months. The infection is often seen in the daycare setting and has a more dramatic presentation in young children than in adults, who often have no symptoms. Rotavirus causes copious amounts of watery diarrhea, vomiting, abdominal pain and low-grade fever. As previously stated, it is often self-limited, meaning it resolves without treatment. It is however, not without complications. The most common complication of Rotavirus is dehydration that can lead to shock and then organ damage. Though the incidence of death attributable to Rotavirus is small in the United States, worldwide, Rotavirus claims more than 500,000 lives yearly. With this statistic, it is easy to see the need for vaccination against Rotavirus, especially in the developing world.

Intussusception is a relatively rare condition seen most often in infants. It is due to the passage of one segment of the intestines into another segment. This abnormality leads to the development of characteristic symptoms. The parents of the infant often report the passage of stool that resemble “currant jelly”, meaning that the stool is mixed with what appears to be mucus and some bloody material. The child is also noted to have intermittent bouts of severe abdominal pain, lethargy and an abdominal mass that is “sausage-shaped”.

The story of the link between Intussusception and Rotavirus vaccination begins in 1999, when Wyeth Lederle (now Pfizer Pharmaceuticals) was forced to withdraw their Rotavirus Vaccine, Rotashield, from the market after an association was made between the vaccine and the development of intussusception. In the years that followed, Merck and GlaxoSmithKline released their versions of the Rotavirus vaccine, named RotaTeq (RV5) and Rotarix (RV1) respectively. Because of the association previously made between intussusception and RotaShield, RV5 and RV1 faced a significant amount of scrutiny. The Center for Biologics Evaluation and Research of the Food and Drug Administration initiated the current study, investigating any possible links between RV5 and RV1 with intussusception.

The study involved a population of 343 children aged 5 to 36.9 weeks who had received either the RV5 (in 3 doses at 2, 4 and 6 months) or the RV1 (in 2 doses at 2 and 4 months) vaccination. Results show a statistically significant increase in the risk of intussusception in infants after receiving the first dose of RV5. The risk is highest in the first 7 days following vaccination. There was no significant increased risk seen with the 2nd and 3rd doses. There was also no significant increase in risk seen in infants after either dose of RV1.

Ultimately, results show that though there is an increased risk of intussusception in children receiving the RV5 vaccination for Rotavirus, this risk is still one tenth the risk that was seen with Rotashield. Therefore, it is appropriate to concluded that though there is risk in vaccination with RV5, this risk is a substantial reduction from first generation Rotavirus vaccination. Also, the risk of such an event is low compared with the overall disease, supporting the health benefits of vaccination.

What this means for you?
Vaccination in children is a topic of great concern among many parents. Fortunately the newer generation of Rotavirus vaccines has shown a far weaker association with intussusception than older vaccines. Please speak to your child’s pediatrician if you have any concerns about the safety of these vaccines.

Yih W. K, Lieu T, Kulldorff M, Martin D, McMahill-Walrave C, Platt R, Selvam N, Selvam M, Lee G, Nguyen M. Intussusception Risk after Rotavirus Vaccination in U.S. Infants. The New England Journal of Medicine. 2014 Feb 6; 370(6):503-512.

Table of Contents Image: