Rotavirus vaccines pass big safety tests.

The largest corporate-funded medical trials in history indicate that two new vaccines against rotavirus, a leading cause of childhood mortality worldwide, are both effective and safe.

Rotavirus causes childhood diarrhea and is responsible for several hundred thousand deaths each year, mostly in developing countries.

Merck & Co. of Whitehouse Station, N.J., calls its vaccine RotaTeq, and London-based GlaxoSmithKline calls its product Rotarix. Smaller trims had already shown that both vaccines prevent illness, and Rotarix has been in use in Mexico since 2004.

In the late 1990s, a separate rotavirus vaccine was abandoned after researchers determined that it occasionally caused a dangerous intestinal blockage (SN: 9/27/03, p. 2O4). To reduce the possibility of such side effects, the manufacturer of the new vaccines launched separate clinical trials, each one including some 60,000 children.

Neither new vaccine is associated with intestinal blockages or other problems, according to reports of the trims in the Jan. 5 New England Journal of Medicine. Rotarix prevented 85 percent of severe illnesses, and RotaTeq prevented 98 percent.--B.H.