RotaTeq: Progress toward developing world access.

Phase III studies of an oral, live, pentavalent, human-bovine reassortant rotavirus vaccine (RotaTeq; Merck) in developed countries have demonstrated that it is well tolerated with regard to intussusception and other adverse events and is efficacious in preventing rotavirus gastroenteritis and associated healthcare encounters. However, it cannot be assumed that rotavirus vaccines will be equally efficacious in infants and young children in the developing world. Differences in host populations, associated health conditions, and the epidemiology of rotavirus disease could affect vaccine performance. Concern about the potential for differences in efficacy stems from studies of previous candidate rotavirus vaccines, including bovine and rhesus rotaviruses, which showed no or variable efficacy in developing regions. Given this history, the World Health Organization (WHO) recommended that the efficacy of "new" rotavirus vaccines should be demonstrated in diverse geographic areas, including developing countries, before widespread implementation. Successful implementation of any rotavirus vaccine in the developing world requires additional clinical research and sharing of early introduction experiences. We discuss efforts to bring RotaTeq vaccine to the developing world. Critical steps to achieve this goal include the clinical evaluation of vaccine safety and efficacy in a multisite trial in Asia and Africa, evaluation of concomitant use with other pediatric vaccines routinely used, and vaccine assessment in special populations (premature, human immunodeficiency virus-infected, and malnourished infants). Completion of WHO prequalification of RotaTeq and affordability are also key requirements to routine vaccine introduction. The RotaTeq Partnership with the Nicaraguan Ministry of Health provides an example of the successful introduction of this vaccine into a developing world country.