August 6, 2010

New studies reveal dramatic potential of rotavirus vaccines in Asia and Africa

Two new studies published today in the Lancet add to a growing body of evidence on the safety, efficacy, and lifesaving potential of rotavirus vaccines in low-income settings of Asia and Africa; where the virus takes its greatest toll.

The studies, co-sponsored by the PATH Rotavirus Vaccine Program and conducted at clinical research sites in Ghana, Kenya, Mali, Bangladesh, and Vietnam, found that rotavirus vaccines significantly reduced severe disease among infants through two years of follow-up. In Asia, the RotaTeq vaccine by Merck and Co., Inc., slashed severe rotavirus disease by half (51 percent) during the first year of life, when children are at greatest risk for diarrhea-related morbidity and mortality. Through two years of follow-up, the vaccine prevented 48.3 percent of severe rotavirus disease.

The study in Africa adds to unprecedented data generated by PATH and its partners in impoverished settings of that region. RotaTeq reduced severe disease by 64.2 percent in African infants during the first year of life and by nearly 40 percent through two years.

Though the efficacy found in these regions is lower than efficacy in industrialized countries, the data suggest that wide use of rotavirus vaccines could save hundreds of thousands of children’s lives each year in Asia and Africa, given the high burden of diarrhea mortality. The potential impact could even be greater than demonstrated by efficacy figures, as countries that have introduced rotavirus vaccines are recording not only major reductions in disease among vaccinated children, but also among unvaccinated children, suggesting a possible herd immunity effect.

The PATH Rotavirus Vaccine Trials Partnership is a collaboration between PATH, WHO, the US CDC, clinical study sites, and vaccine manufacturers. The partnership’s activities are funded by the GAVI Alliance.