BACKGROUND:
The possibility of a global switch from current oral polio vaccine (OPV) to inactivated polio vaccine (IPV) after global eradication of polio s being debated. One of the concerns about such a switch is that the cost may be prohibitively high for developing countries.

OBJECTIVE:
This study estimates the incremental cost of a vaccine switch from OPV to IPV in developing countries.

METHOD:
Data for costing the vaccine switch were collected from a global review of publications. The incremental cost was modelled by using a Excel model.

RESULT:
The switch from OPV to IPV for all developing countries together will result in an increase in total annual cost of $317 million, averaging $2.91 per child. Overall, in developing countries the switch will need $1 million to avoid a case of vaccine-associated poliomyelitis paralysis through the switch of vaccines. For the low-coverage countries, the vaccine switch will lead to a net increase in costs of about $26 million, averaging about $2.42 per target child. For intermediate-coverage countries, the switch will result in an increase in total cost of $129 million, averaging about $2.68 per target child. For high-coverage countries, it will result in an increase in the total cost of $162 million, an average of about $3.26 per target child.

CONCLUSION:
A switch to an IPV-only would entail significant incremental costs and introduce additional epidemiological risks, including unsafe injections and the release of wild virus in the IPV production process. The benefit of the switch would come from elimination of: (1) a limited number of vaccine associated polio paralyses and (2) a few polio cases caused by circulating vaccine-derived poliovirus. These benefits ultimately will need to be weighed against the high incremental costs and increased risks that would come with the switch.

LEARNING OBJECTIVES:
The participants would:
(1) Gain knowledge on the current debate of vaccine choice in the Global Vaccine Program;
(2) Understand the methods of incremental cost analysis
(3) Participate in the debate in the immunization strategies after global eradication of polio.