PATH’s Center for Vaccine Innovation and Access

Rotavirus

A comprehensive approach to rotavirus vaccines

Photo: PATH/Mike Wang

Photo: PATH/Mike Wang

Diarrhea is a leading killer of young children worldwide, and vaccines are an essential and lifesaving part of diarrhea control strategies. For this reason, PATH pursues a wide range of work related to vaccines against the leading causes of this serious disease—rotavirus, enterotoxigenic Escherichia coli (ETEC), and Shigella.

Rotavirus is the most common cause of severe diarrhea. In 2013, rotavirus killed 215,000 children younger than five years and hospitalized millions more. Severe rotavirus disease can also result in longer-term health issues, such as developmental deficiencies and stunting. Vaccination has proved to be the best way to protect children from the deadly dehydrating diarrhea that rotavirus can cause. The reductions in severe and fatal diarrhea experienced in countries that have introduced rotavirus vaccines underscore the potential of these vaccines to improve child health and save lives.

Although rotavirus vaccines are currently available and recommended for global use by the World Health Organization (WHO), they are not yet widely available in or affordable for low-resource countries, where more than 90 percent of rotavirus-related deaths occur. To address this challenge, PATH is working on two fronts: to increase access to and effectiveness of existing rotavirus vaccines worldwide, and to speed the development of safe, effective, and more affordable new rotavirus vaccines. We also lead advocacy efforts to increase awareness of both diarrheal disease and the ways in which an array of interventions, including vaccines, can save lives.

Rotavirus vaccine access, effectiveness, and impact

PATH partners with global health leaders to provide technical assistance to countries in Africa and Asia that are preparing for rotavirus vaccine introduction with support from Gavi, the Vaccine Alliance. In addition, we are conducting studies to identify ways to improve or enhance the performance of globally available rotavirus vaccines in low-resource settings in an effort to maximize their benefits in countries where the burden is greatest. We also conduct health economic analyses related to rotavirus vaccine impact and cost-effectiveness to help inform vaccine introduction efforts.

Accelerating the development of new rotavirus vaccine options

PATH is also supporting the development of several promising new rotavirus vaccines, because bringing new vaccines to the global market is critical to improving affordability and ensuring a sustainable supply. Our most advanced candidate is the oral, live attenuated, bovine-human reassortant vaccine (BRV), based on a construct developed by the US National Institutes of Health.

We are working with Serum Institute of India, Pvt., Ltd. (SIIPL) to conduct a Phase 3 efficacy trial of this pentavalent BRV candidate. The three-year trial, launched in May 2014, is being conducted with 7,500 infants at six study sites across India. If successful, SIIPL plans to register the vaccine for use in India first and then will seek to have it prequalified by WHO. To support this effort, SIIPL and PATH are conducting a parallel study in 1,500 additional infants to gather other data required by WHO. In addition, SIIPL and PATH are developing a second-generation, single-vessel, liquid BRV candidate that may be preferred in some countries.

PATH is also evaluating non-replicating rotavirus vaccine candidates that may offer a promising alternative approach to improving protection through rotavirus vaccination. This type of rotavirus vaccine would be administered as an intramuscular injection, and could potentially overcome the lower efficacy levels of oral, live attenuated vaccines seen in low-resource settings. Encouraging results are currently moving our most advanced candidate through pivotal clinical studies in South Africa.

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