Expanded Program on Immunization
WHO initiated the EPI in 1974 to provide countries with guidance and support to improve vaccine delivery and to help make vaccines available for all children (Hadler and others 2004; Turk 1982; WHO 1974). A standard immunization schedule was established in 1984 on the basis of a review of immunological data for the original EPI vaccines: BCG, diphtheria-tetanus-pertussis (DTP), oral polio, and measles vaccines (Halsey and Galazka 1985).
Today, national immunization programs in developing countries are responsible for improving access to the traditional EPI antigens and introducing new vaccines. In 2002, the EPI introduced the Reaching Every District strategy, which focused on achieving an 80 percent coverage rate of DTP3 in 80 percent of districts and using immunization contacts to deliver other high-priority child health interventions. In addition to delivering vaccinations, national immunization programs are concerned with the quality and safety of immunization through the adoption of safe injection technologies (autodisabled syringes, storage boxes, and incinerators) and proper cold chain and vaccine stock maintenance.
In most developing countries, immunizations are provided through a system of fixed facilities at different levels of the health system. Immunization campaigns are discrete, time-limited efforts at national or subnational levels that usually focus on specific antigens (for example, polio). Mobile strategies rely on the use of specialized vehicles to transport health professionals and vaccines to deliver services to remote or migrating populations. Outreach is a strategy by which staff members from a health facility travel to villages and surrounding areas to administer vaccines. Extended outreach refers to more targeted and intensive efforts.
In 1999, the major international development partners involved in immunization (for example, WHO, UNICEF, the World Bank, and bilateral donors) joined the Bill & Melinda Gates and Rockefeller Foundations, the vaccine industry, and nongovernmental organizations to create GAVI (http://www.vaccinealliance.org) to increase access to new and underused vaccines in the world's poorest countries, improve access to basic immunization services, and accelerate research and development pertaining to new vaccines and delivery technology. Through the Vaccine Fund, GAVI raised more than US$1.3 billion to strengthen immunization systems, introduce new vaccines, and support safe injection practices. More than US$3 billion has been pledged for the next 10 years. Between 2000 and 2003, an additional 4 million children were vaccinated with DTP3, 42 million with hepatitis B, nearly 5 million with Hib, and more than 3 million with yellow fever vaccine.
