This is an open-label phase IV randomized clinical trial that will compare immune responses among infants who receive different dose schedules of either fractional dose or full dose inactivated poliovirus vaccine (IPV), delivered either intramuscularly or intradermally. Note: This study was terminated early due to the COVID-19 pandemic. Due to early study closure, the study objectives could not be evaluated as planned. Both of the primary objectives and several secondary objectives could not be evaluated because none of the study participants reached the corresponding endpoint. Due to limited sample size, the analysis approach for four secondary objectives was changed from a non-inferiority assessment to a comparison of proportions between groups.
Oral poliovirus vaccine (OPV) cessation is essential to achieve eradication of polio as OPV contains live poliovirus, which can mutate and become neurovirulent. After OPV cessation, inactivated poliovirus vaccine (IPV) will be the only polio vaccine used for routine immunization. This clinical trial will provide poliovirus type-specific immunogenicity data on an IPV or fractional-dose IPV (fIPV)-only schedule for routine immunization, which will be important for post OPV cessation era. For fIPV, it will provide immunogenicity data on fIPV administered either intradermally (ID) or intramuscularly (IM) and allow a direct comparison of the two methods. Healthy infants 6 weeks of age will be enrolled at two study clinics in Dhaka, Bangladesh, and randomized to one of seven study arms. Infants will be followed-up until 10 months of age through clinic visits. Blood specimens will be collected to test for immunological response.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
958
Fractional dose of inactivated poliovirus vaccine that protects against types 1, 2, and 3 (all polio serotypes). Given as a 0.1 milliliter (mL) dose (fractional) by intradermal (ID) injection in lieu of the full 0.5 mL dose.
Fractional dose of inactivated poliovirus vaccine that protects against types 1, 2, and 3 (all polio serotypes). Given as a 0.1 milliliter (mL) dose (fractional) by intramuscular (IM) injection in lieu of the full 0.5 mL dose.
Fractional dose of inactivated poliovirus vaccine that protects against types 1, 2, and 3 (all polio serotypes). Given as a 0.2 milliliter (mL) dose (fractional) by intramuscular (IM) injection in lieu of the full 0.5 mL dose.
Full dose of inactivated poliovirus vaccine that protects against types 1, 2, and 3 (all polio serotypes). Given as a 0.5 milliliter (mL) dose by intramuscular (IM) injection.
icddr,b study clinics (Mirpur and CTU Dhaka)
Dhaka, Bangladesh
Vaccine response
Dichotomous (yes/no) variable defined as participants who are either seronegative (\<1:8 titers) at baseline who become seropositive (≥1:8) after vaccination (seroconversion) or participants who demonstrate a four-fold rise in titers after vaccination between two specimens, e.g. a change from 1:8 to 1:32, after adjusting for expected decay in maternal antibodies. Antibody titers at 6 weeks of age will be the starting point for the expected decline in maternal antibodies, assuming at half-life of 28 days.
Time frame: Measured four weeks after administration of study vaccine(s).
Reciprocal antibody titers
Variable of the observed reciprocal antibody titer results.
Time frame: Measured four weeks after administration of study vaccine(s).
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