Inactivated Polio Vaccine(NanoPass Technologies)

This study is an open-label phase III randomized clinical trial that would compare immunogenicity after receiving one of five different combinations of polio vaccines. Infants will be enrolled and randomized at 6 weeks of age to one of five different arms:
A) Three doses of trivalent oral poliovirus vaccine (tOPV) at 6, 10 and 14 weeks of age B) Three doses of bivalent OPV (bOPV) at 6, 10 and 14 weeks of age C) Two doses of intramuscular (IM) inactivated poliovirus vaccine (IPV) at 6 and 14 weeks of age D) Two doses of intra-dermal (ID) fractional IPV (f-IPV) at 6 and 14 weeks of age E) Sequential administration of ID f-IPV at 6 and 14 weeks of age with bOPV at 10 weeks of age To assess the immunogenicity of each study vaccine and vaccination schedule, antibody titers against poliovirus types 1, 2 and 3 will be determined in sera extracted from blood collected before (at 6 weeks of age) and after receiving 3 doses of study vaccine (18 weeks of age). Seroconversion will be defined as a titer 4-fold higher than the expected fall in maternally derived antibodies, assuming a half-life of 28 days. The initial antibody titer at 6 weeks of age will be used as the starting point for the expected decline in maternal antibody.
This study will compare the immunogenicity of:
Sequential dose of intra-dermal f-IPV and bOPV to bOPV alone administered at 6, 10 and 14 weeks of age
tOPV to bOPV administered at 6,10 and 14 weeks of age
IM IPV to ID f-IPV administered at 6 and 14 weeks of age The answer to these questions will guide the global polio eradication program in designing new routine immunization schedule for children that eliminates the risks of paralysis due to vaccine derived poliovirus (VDPV) from type 2 vaccine poliovirus.