Health Information

FOCUS ON IMMUNIZATIONS     John D. Grabenstein, Section Advisor

Key points: Compared with 15 previous prevaccine seasons, the most recent U.S. rotavirus season appears to be delayed in onset and diminished in magnitude. This change coincides with the use of live oral pentavalent rotavirus vaccine (Rota-Teq—Merck). Subsequently, another brand of rotavirus vaccine has been licensed in the United States (Rotarix—GlaxoSmithKline).

Finer points: Rotavirus activity data were collected by the National Respiratory and Enteric Virus Surveillance System and the New Vaccine Surveillance Network and recently summarized by CDC. Compared with the 1991–2006 U.S. seasons, the 2007–2008 rotavirus season was characterized by a delayed onset of 2 to 4 months and a diminished magnitude of greater than 50%. This change coincides with FDA approval of a pentavalent rotavirus vaccine and its incorporation into the Advisory Committee on Immunization Practices immunization schedule in February 2006.

What you need to know: Rotavirus is the leading cause of severe, acute viral gastroenteritis in infants and young children. In 2004, an estimated 527,000 deaths worldwide in children younger than 5 years were attributed to rotavirus infection. While rotavirus infection rarely leads to death in the United States, more than 55,000 hospitalizations and 200,000 emergency department visits are attributed to infection with the virus each year.

Rotavirus vaccine is given orally as a 2- or 3-dose series beginning at 2 months of age to prevent gastroenteritis caused by infection with the virus. The first dose may be given to infants as early as 6 weeks of age and the last dose should be administered by 8 months of age. The rotavirus vaccine is contraindicated in patients with a history of anaphylaxis to the vaccine or to any of its components. It should be used cautiously in patients with moderate or severe acute illness, altered immunocompetence, moderate to severe acute gastroenteritis or chronic gastrointestinal disease, and a history of intussusception.

The data summarized by CDC are population based and may not be nationally representative. Other data limitations include the need to further evaluate the 2007–2008 rotavirus season, as it was ongoing at the time of data review. Testing for rotavirus is not a routine clinical practice and varies based on institution policy, so a decrease in the amount of testing may cause less rotavirus activity to be reported. Continued surveillance and additional studies are needed to confirm the effects of vaccination on rotavirus activity during this and future seasons.

What your patients need to know: Tell parents that the rotavirus vaccine appears to delay and reduce infection when administered as recommended. Address concerns about vaccination that could potentially delay administration, as guidelines recommend that the rotavirus vaccination series be started no later than the infant's 14th week of life. Explain to patients that the associated benefits of vaccination far outweigh the potential risks.