Vaccination of U.S. infants against rotavirus appears to provide indirect protection to older children and adults, according to a recent analysis (J Infect Dis. 2011;204:980-986).

In 2006, the CDC recommended routine vaccination against rotavirus, a major cause of severe diarrhea in infants and young children. By January 2008, approximately 57% of children younger than age 1 year and 17% of 1-year-olds were vaccinated.

An analysis of nationally representative data from 2000-2008 shows that rates of all-cause diarrhea hospitalizations among children younger than age 5 years during the 2008 rotavirus season declined by 46%. Significant reductions were also seen in the 5-14-year and 15-24-year age groups, particularly in March — the historic peak rotavirus month in the prevaccine era — and particularly among 24-year-olds, who were not eligible for the vaccine.

These findings suggest that rotavirus vaccination has also reduced transmission of wild virus, thereby providing indirect protection.

Vaccines in general were the subject of another recent report, this one issued by the Institute of Medicine (IOM). On reviewing more than 1,000 research articles, a committee of experts found no links between autism and some serious conditions that have raised concerns, including type 1 diabetes and autism.

Convincing evidence was found showing 14 health outcomes — including seizures, inflammation of the brain, and fainting — that can be caused by certain vaccines, although these outcomes occur rarely. Indicative but less clear data were found on associations between specific vaccines and four other effects, such as allergic reactions and temporary joint pain.

The report, Adverse Effects of Vaccines: Evidence and Causality, is available online.