Hepatitis B virus (HBV) infection and Hib related diseases are important public health problems in Zambia. Zambia submitted its application to GAVI for pentavalent vaccine that includes both HBV and Hib antigens in 2001. However, due to vaccine production failure, the Ministry of Health decided in January 2003, to introduce liquid-lyophilised tetravalent, DTP+Hib in January 2004 and switch to liquid-lyophilised pentavalent, DTP-HepB+Hib in 2005. Following the availability of the fully liquid formulation late in 2006, the country eventually switched to the fully liquid formulation in February 2007.
A post introduction evaluation (PIE) is recommended by WHO for all countries that have introduced a new vaccine, ideally within 6-12 months of introduction. The PIE in Zambia was specifically aimed at assessing the programmatic impact of switching from the liquid-lyophilised to fully liquid pentavalent vaccine. The Zambia PIE evaluation team was composed of representatives from: WHO, UNICEF, CDC, USAID and the Ministry of Health (MOH). Four provinces were selected based on criteria of good, medium and poor coverage performance and diversity of population size.
