A new inactivated polio vaccine based on attenuated poliovirus strains was developed to transfer the technology to manufacturers in low- and middle-income countries. This vaccine was produced in different dosages and in different formulations. In healthy adults the safety of the highest dose was comparable to that of the existing inactivated polio vaccine. The purpose of this trial is to determine the safety of the different dosages and formulations of the vaccine in infants. The second goal of this study is to analyse the immune response after three doses in infants.