Rotavirus Vaccine Reported Intussusception Cases Fall Within Expected Range

The Centers for Disease Control and Prevention (CDC) released new safety data on a recently licensed rotavirus vaccine given to infants that indicate the vaccine does not pose an elevated risk for intussusception, the most common cause of bowel obstruction in infants.

The vaccine, sold by Merck and Company under the brand name RotaTeq, was licensed by the U.S. Food and Drug Administration (FDA) in February 2006. The Advisory Committee on Immunization Practices (ACIP) recommends RotaTeq for routine vaccination of U.S. infants to protect against rotavirus, which causes severe diarrhea, vomiting, fever and dehydration (gastroenteritis) in children.

Each year in the United States, rotavirus is responsible for more than 400,000 doctor visits; more than 200,000 emergency room visits; and 55,000 to 70,000 hospitalizations. In developing countries, rotavirus is a major cause of childhood deaths, estimated to cause more than half a million deaths each year in children younger than 5 years of age.

Last month, FDA notified healthcare providers and consumers that it had received reports of intussusception following RotaTeq vaccination. Since then, FDA, ACIP and CDC have concluded that the number of intussusception reports after administration of RotaTeq has not exceeded the number expected to occur without vaccination and that the vaccine does not appear to be associated with intussusception.

"Monitoring the safety of a new vaccine is very important," said Anne Schuchat, M.D., director of CDC's National Center for Immunization and Respiratory Diseases. "The data we have reviewed are reassuring, and we continue to recommend the RotaTeq vaccine. However, we will continue to carefully monitor reports of possible adverse effects associated with the vaccine and will take appropriate action if there proves to be a problem in the future."

Based on ACIP recommendations, CDC policy calls for routine immunization of all U.S. infants with three doses of RotaTeq administered orally at 2, 4 and 6 months.

RotaTeq is the only vaccine approved in the United States for prevention of rotavirus disease. Studies indicate RotaTeq will prevent about 74 percent of all rotavirus cases and about 98 percent of the most severe cases, including 96 percent of cases requiring hospitalization.

Intussusception is a serious, life-threatening condition that occurs when the intestine or bowel becomes blocked. The condition can occur spontaneously in the absence of vaccination. It is most common among infants in the first year of life, causing about 1,400 infant hospitalizations annually. These cases occurred before use of any rotavirus vaccines in the United States.

The reported intussusception cases were detected through routine monitoring of new vaccines using the Vaccine Adverse Event Reporting System (VAERS). Following licensure and general use of all vaccines in the United States, CDC and FDA closely monitor VAERS reports of potential health problems after vaccination submitted by a variety of sources. Reports to VAERS may be submitted by anyone, including healthcare providers, patients and family members. Physicians and scientists at both agencies review all reports of serious side effects reported to VAERS.

CDC and FDA continue to closely monitor RotaTeq for problems in vaccine recipients. They encourage all healthcare providers and other individuals to report any cases of intussusception or other serious adverse events to VAERS.