Rotavirus Vaccine Reduces (Surprise) Rotavirus Disease

The onset of this year's rotavirus season was delayed by 2-4 months, and its magnitude was reduced by more than 50%, when compared with the previous 15 seasons of viral activity. These data coincide with the increasing use of the rotavirus vaccine (RotaTeq; Merck) in infants, according to an early release report from the MMWR. The live, oral vaccine was approved by the FDA in 2006, and its routine administration at 2, 4, and 6 months of age is recommended by the CDC's Advisory Committee on Immunization Practices.

Data from the National Respiratory and Enteric Virus Surveillance System (NREVSS) and the New Vaccine Surveillance Network* (NVSN) indicate that this year's rotavirus season began in late February, while the median onset of seasons during 1991-2006 occurred in mid-November (MMWR figure). Also the proportion of all positive rotavirus tests from mid-November 2007 to mid-April 2008 was substantially lower than the minimum number of positive tests during the previous 15 years.

Percentage of Positive Rotavirus Tests From NREVSS
(Data from 2008 are current through May 3)

According to the CDC, the mean coverage with 1 dose of rotavirus vaccine among 3-month-old infants was 49% in May 2007 and 56% in May 2008. In 13-month-old infants, mean coverage with 3 doses was 3.4% and 33.7% in May 2007 and May 2008, respectively. Rotavirus, the leading cause of severe, acute gastroenteritis in young children worldwide, results in up to 70,000 hospitalizations, 272,000 ED visits, and 410,000 office visits in the United States each year.

*Data are from Monroe County, NY; Hamilton County, OH; and Davidson County, TN.