Vaccines are considered as one of the most successful medical inventions against various infectious diseases (Hilleman, 2000
). In 1974, the World Health Organization (WHO) officially launched a global immunization programme called Expanded Programme on Immunization (EPI). The ultimate aim of EPI was to protect the child population across the globe against vaccine preventable diseases in general and particularly diphtheria, whooping cough, tetanus, polio, tuberculosis and measles by the year 2000. Particular in the year 1984, World Health Organization established the uniform vaccine schedule for diphtheria, whooping cough, tetanus, polio, tuberculosis and measles. The high proportion of chronic infection that is acquired during childhood can be prevented by routine infant immunization programme.
The Expanded Programme on Immunization is now renamed as Universal Immunization Programme (UIP). The EPI was launched in 1978 in India after successful global eradication of small pox in 1975 through effective vaccination programmes and strengthened surveillance. The WHO global advisory group of Expanded Programme on Immunization in the year 1991 recommended that by the year 1997, accordingly, hepatitis B vaccine should be introduced into national immunization programme across countries around the globe because of high rate of incidence of chronic infectious diseases that could affect during childhood by hepatitis B virus. Accordingly, this vaccine (hepatitis B) has been included in the national immunization programme in more than 130 countries (Kane, 1998
). Later, yellow fever and Haemophilus influenzae meningitis (Hib) vaccines have been added in countries with a high burden of disease (Fiore et al., 2009
Vaccine development and immunization constitute critical component of public health policy in any nation. Accordingly, the Global Programme for Vaccines and Immunization (GPV) was established in 1994 and this programme thus had the terms of orientation that span from vaccine research through vaccine production and quality control to help policy matter of health plan and provide their services to control vaccine preventable diseases. The Children’s Vaccine Initiative (CVI) is a companion organization to the Global Programme for Vaccines and Immunization and has its own strategic plan. The purpose of CVI is to develop new technologies to progress and develop a single shot efficient vaccine. It should be given as a single dose (preferably by oral). It is effective when administered near birth, heat stable, contains multiple antigens and highly effective against wide variety of diseases. With a particular focus on the world BPL (below poverty line) children, GPV aims at strengthening routine immunization services, increasing wide coverage and introducing novel generic vaccines. Global Alliance for Vaccines and Immunization (GAVI), an advisory group comprising National Governments and International agencies such as WHO, World Bank, UNICEF and industries was launched on January, 2000. GAVI’s mission statement is “To save children’s lives and protect people’s health through wide spread use of vaccines with a particular emphasis on developing countries”. As an alliance of major leaders in International health and development, GAVI has great potential in decision making among policy makers and donors on the value of vaccination for reducing poverty and infant mortality in the developing countries.
The decision to introduce a vaccine into EPI is greatly influenced by a number of factors such as bio-burden, epidemiological aspects with special reference to transmission, vaccine factors that include safety, efficacy and availability, feasibility of introduction, financial implications and projected or expected benefits in terms of morbidity, mortality and cost effectiveness. Thus a vaccine that is ideal for introduction in to EPI would be one that is highly efficacious, economical, safe and protects against disease. Therefore, in designing effective vaccines certain key elements are essential such as:
1. An antigen that can stimulate good immune response.
2. Presentation of antigens in order to augment the immune response.
3. Presentation of antigens in native form.
Stimulation of innate immune system is an important role in the evolution of adaptive immune response (Hobe et al., 2004
). Therefore, inclusion of immune potentiators (adjuvants), which triggers a robust and long lasting immune response, is of primary importance.