Rotavirus is a leading cause of severe acute gastroenteritis in infants and young children.

The virus causes more than 2 million hospitalizations for diarrhea, vomiting and dehydration, and nearly 600,000 deaths among children under five—approximately one child per minute—worldwide each year. Eighty percent of rotavirus-related deaths occur in developing countries. ROTATEQ^® (rotavirus vaccine, live, oral pentavalent), a vaccine to help prevent rotavirus disease, has been available in the United States since 2006.

The Partnership

In 2006, Merck and the Nicaraguan Ministry of Health announced a new partnership at the Clinton Global Initiative through which all eligible infants born in Nicaragua in a three-year period would receive free doses of Merck's ROTATEQ, an oral, ready-to-use vaccine that helps to prevent rotavirus gastroenteritis. Through this partnership, ROTATEQ was made available in a developing country in the same year it became available in a developed country.

In addition to the Nicaraguan Ministry of Health, other partners in the program included the Pan American Health Organization (PAHO), the United Nations Children's Fund (UNICEF), The Nicaraguan Pediatric and Medical Societies and NICASALUD/FAMISALUD, a national consortium of nongovernmental organizations working in the country supported by the U.S. Agency for International Development. Rotavirus was a significant public health issue in Nicaragua prior to 2006:

• In 2005, rotavirus outbreaks peaked in Nicaragua.
• 64,088 cases and 56 deaths due to diarrhea were reported.
• 73 percent of the cases and 100 percent of all deaths due to diarrhea were among young children (<5 years of age).

The Merck effort has assisted Nicaragua to establish rapidly a national rotavirus vaccination program to help protect infants from this potentially serious disease. Since the partnership was launched in October 2006, Merck assistance provided over 1.3 million doses of ROTATEQ to Nicaragua for use in the national immunization program. The country has achieved rates of rotavirus vaccination that are among the highest in the world with more than 90 percent of children vaccinated.

In the past, hospitals in Nicaragua every winter saw an increase in infants and children suffering from severe diarrhea and dehydration, much of which was caused by rotavirus gastroenteritis. Two separate scientific studies were conducted in Nicaragua to evaluate how well a three-dose regimen of the vaccine worked in actual practice. The first study showed that the effectiveness of the vaccine during one year of followup against rotavirus disease requiring admission or treatment with intravenous hydration was 46 percent and the effectiveness against severe and very severe rotavirus diarrhea was 58 percent and 77 percent, respectively. The second study showed that the effectiveness during two years of followup against severe disease ranged from 64–84 percent. The second study also found that for children under one year of age, who are at greatest risk of severe disease, the vaccine was 85 percent effective against severe rotavirus disease.

In addition to helping protect infants and young children from rotavirus, in this partnership Merck provided assistance in administrative, training and logistical aspects related to an expansion of Nicaragua's immunization calendar to include rotavirus vaccine, in strengthening local rotavirus surveillance networks, and in assessing the public health benefit resulting from the early adoption and use of a rotavirus vaccine.

After completion of the pilot in October 2009, sustainability of Nicaragua's vaccination program was ensured by the GAVI commitment to support rotavirus vaccination and by contributions from the Nicaraguan government. Data from this three-year partnership project suggest a significant positive public health impact of ROTATEQ for children at risk for rotavirus gastroenteritis in Nicaragua, the first GAVI-eligible country to introduce rotavirus vaccine.

In 2005, the World Health Organization (WHO) moved to recommend rotavirus vaccination as one of the core list of childhood immunizations. In late 2006, the GAVI Alliance committed to provide funding for the introduction of rotavirus vaccines in eligible countries around the world. In 2009, the WHO recommended the inclusion of rotavirus vaccination of infants into all national immunization programs.