Hexavalent IPV-based combination vaccines for public-sector markets of low-resource countries

In anticipation of the successful eradication of wild polio virus, alternative vaccination strategies for public-sector markets of low-resource countries are extremely important, but are still under development. Following polio eradication, inactivated polio vaccine (IPV) would be the only polio vaccine available, and would be needed for early childhood immunization for several years, as maintenance of herd immunity will be important for sustaining polio eradication. Low-cost combination vaccines containing IPV could provide reliable and continuous immunization in the post-polio eradication period. Combination vaccines can potentially simplify complex pediatric routine immunization schedules, improve compliance, and reduce costs. Hexavalent vaccines containing Diphtheria (D), Tetanus (T), whole cell pertussis (wP), Hepatitis B (HBV), Haemophilus b (Hib) and the three IPV serotype antigens have been considered as the ultimate combination vaccine for routine immunization. This product review evaluates potential hexavalent vaccine candidates by composition, probable time to market, expected cost of goods, presentation, and technical feasibility and offers suggestions for development of low-cost hexavalent combination vaccines. Because there are significant technical challenges facing wP-based hexavalent vaccine development, this review also discusses other alternative approaches to hexavalent that could also ensure a timely and reliable supply of low-cost IPV based combination vaccines.