Implementation of infant rotavirus vaccination appears to be linked to a decrease in rates of gastroenteritis hospitalization among older children and adults, according to published research.
“Implementation of infant rotavirus vaccination in 2006 has substantially reduced the burden of severe gastroenteritis among U.S. children younger than 5 years,” Paul A. Gastanaduy, MD, MPH, of the CDC, and colleagues wrote as background information in the Aug. 28 issue of the Journal of the American Medical Association.
To determine whether reduced transmission of rotavirus extends indirect protection to older children and adults, the researchers assessed patterns of gastroenteritis hospitalizations among children 5 and older and among adults before and after implementation of infant rotavirus immunization.
Rotavirus-coded and cause-unspecified gastroenteritis discharges from January 2000 through December 2010 were retrieved from a nationally representative database of hospital inpatient stays, the Nationwide Inpatient Sample. Estimates were determined of annual and monthly incidence rate ratios of the postvaccine years (2008, 2009 and 2010) separately and combined versus the prevaccine years (2000-06; 2007 was a transition year with limited coverage and was excluded).
During 2008-10, statistically significant reductions compared with prevaccine years were observed in rotavirus-coded discharges in the age groups 0-4 years, 5-14 years and 15-24 years. Similarly, significant reductions were observed in cause-unspecified gastroenteritis discharges in those three age groups and the age group 25-44 years.
The authors wrote that compared with prevaccine years, significant reductions in rotavirus-coded discharges occurred for patients up to age 25 in 2008 and age 15 in 2009, and across all age groups in 2010. Similar patterns were observed for cause-unspecified gastroenteritis discharges. In all age groups and all postvaccine years, cause-unspecified reductions were focused in the late winter and early spring. For 2010, significant reductions were observed in March and April across all age groups.
“The pattern of observed reductions in gastroenteritis discharges among unvaccinated older children and adults is consistent with indirect protection resulting from infant rotavirus vaccination,” the authors wrote. “These results point to the primacy of children in the transmission of rotavirus and illustrate how indirect benefits may amplify the effect of the U.S. rotavirus vaccination program.”
Study access (via subscription or purchase): http://jama.jamanetwork.com/article.aspx?articleid=1733704.