The cost of integrating hepatitis B virus vaccine into national immunization programmes: a case study from Addis Ababa

National programmes of hepatitis B virus (HBV) vaccination are recommended by the World Health Organization for all countries. Countries suffering the highest burden of HBV disease are those most needy of universal vaccinatio n, but are frequently of very low income and resources for health care are scarce. The introduction of HBV vaccination would inevitably stretch these resources further even with support of donor agencies. Thus an assessment o f the cost-effectiveness of HBV vaccination is desirable to assist in decis ion making about resource allocation. We describe here a method for estimat ing the additional costs of introducing HBV vaccination into the Expanded P rogramme on Immunization (EPI) at a national level. Of fundamental importan ce is that this method enables costs to be assessed prior to the introducti on of vaccination. We illustrate the method using a study carried out at th e sub-national level, in the city of Addis Ababa, Ethiopia, but which can b e expanded countrywide. The method, in brief, involved the use of a number of questionnaires which could be used to estimate the costs associated with the EPI programme from a large sample of the static clinics as well as fro m central sources. Since unit costs were collected along with the quantitie s of resources used and estimates of the capacity used for certain faciliti es (such as refrigerators), the additional cost of introducing HBV vaccine could be estimated largely by extrapolation of the resources used in vaccin ating against diphtheria/pertussis/tetanus vaccine (which, similar to HBV v accine, requires three doses). The estimation of costs is only part of the information required to make de cisions on resource allocation, and should be used in association with meas ures of the burden of disease due to the infection in the community and eff ectiveness of the control programme at reducing this burden. The prediction of the tatter, based upon a sound epidemiological understanding of the inf ection, is the subject of a forthcoming paper.