The US Food and Drug Administration (FDA) posted a notification on February 13, 2007, to encourage health care workers to recognize and report possible vaccine adverse events following the introduction of Merck & Co., Inc.’s RotaTeq® vaccine. The notification is intended to provide health care workers with an update on information collected as part of the US Vaccine Adverse Event Reporting System, which is routinely used for tracking vaccine safety. Read the notification on the FDA website.

In February 2006, the Advisory Committee on Immunization Practices (ACIP) to the US Centers for Disease Control (CDC) unanimously recommended routine use of RotaTeq® in US infants to prevent rotavirus, the leading cause of severe diarrhea, vomiting, fever, and dehydration in infants and young children. 

Because of a suspected association between intussusception (a rare, life-threatening blockage of the intestine) and an earlier rotavirus vaccine (RotaShield®), the US CDC and FDA are monitoring the new RotaTeq® vaccine with particular care. Prior to last year’s FDA approval of Merck’s vaccine, investigators conducted a rigorous clinical trial with more than 70,000 subjects and found that RotaTeq® was not associated with an increased risk of intussusception, or other serious adverse events, when compared to placebo.

In the United States, intussusception is estimated to spontaneously occur in approximately one in 2,000 healthy young infants and children per year. While 28 reported cases of intussusception were identified through post-marketing surveillance following administration of RotaTeq®, it is important to note, as the FDA states, the number of intussusception cases reported to date after RotaTeq administration does not exceed expected background rates among unvaccinated children of the same age. In fact, the number of reported cases is lower than expected based on estimates of naturally-occurring episodes of intussusception in children in this age range (CDC, unpublished data).

Media reports of the FDA notice implied a link between the vaccine and intussusception that is not supported by the data. The ACIP conducted their regularly scheduled review of the safety tracking data during their meeting on February 21, 2007.

Click here to read the FDA notice.
Click here to read the vaccine manufacturer’s official response.

RotaFlash is a news update published by the PATH Rotavirus Vaccine Program, a partnership with the US CDC and the World Health Organization. The program is supported by the GAVI Alliance.

Posted February 23, 2007.