Pakistan Short Interval mOPV1 Compared With Standard Interval mOPV1 and bOPV 1,3
Condition: Polio
MeSH terms: Poliomyelitis
Study type: Interventional

Summary: 
      Globally, polio cases have decreased by over 99% since 1988. However, wild poliovirus cases
      continue in Pakistan. Conflict and lack of access to children due to on-going insecurity in
      tribal areas present special challenges in interrupting transmission rapidly. There exists
      limited knowledge on the effect of shorter intervals of mOPV vaccination on immunogenicity
      levels in young children. The aim of this study is to demonstrate the non-inferiority of
      shorter intervals (7 and 14 days) between doses of mOPV1 vaccine compared to the customary
      interval (30 days). A 4th arm will receive bivalent (bOPV) vaccine at standard intervals
      beginning at 6 weeks of age.
    

Detailed description: 
      This randomized clinical trial which will be conducted in 5 low-income areas in and around
      Karachi (4 peri-urban, contiguous coastal villages outside Karachi, and one urban squatter
      settlement) where the Aga Khan University's Department of Paediatrics and Child Health has
      well-established demographic surveillance with all pregnancies and new births in the area
      captured through the system. The study participants will be enrolled from birth until 102
      days. Subjects will be randomized to one of four trial arms.

      All children will receive tOPV at birth. At 42 days (6 weeks) of age, three study arms will
      receive a dose of mOPV1 whereas the fourth arm will receive a dose of bOPV1&3 as per
      protocol. Then 7 or 14 or 30 days later, the study participants in Arms A, B, and C will
      receive a second dose of mOPV1 while a second dose of bOPV 1&3 will be given to participants
      in Arm D at 30 days.

      Name and description of products:

        1. Standard trivalent oral poliovirus vaccine (tOPV), in a 10:1:6 formulation, containing
           at least 106 TCID50 of Sabin -strain poliovirus type 1, at least 105 TCID50 of
           Sabin-strain poliovirus type 2 and at least 105.8 TCID50 of Sabin-strain poliovirus type
           3.

        2. Monovalent type 1 oral poliovirus vaccine (mOPV1) containing at least106 TCID50 of
           Sabin- strain poliovirus type 1.

        3. The bivalent oral polio vaccine containing at least 106 CCID50 of Sabin poliovirus type
           1 and 105•8 CCID50 of Sabin poliovirus type 3.

      Sample Size:

      To show non-inferiority of a 2-dose mOPV1 schedule with shorter-intervals (either 7 or 14
      days) [intervention] compared to a 2-dose mOPV1 schedule administered at 30-day intervals
      [control], and a 2-dose bOPV13 schedule administered at a 30-day interval (control) assuming
      a power of 0.90 (beta) and p of 0.05 (alpha), we require a sample of 139 for each study
      group, for a total of 556 subjects. To compensate for drop out, attrition and insufficient
      sera for laboratory testing, an inflated (by ~ 50%) sample size of 200 in each group will be
      used (total sample size of 800)

      Efficacy Endpoints:

      The primary endpoint is seroconversion with antibodies to poliovirus type 1 following a
      two-dose schedule of mOPV1 given at intervals of 7 and 14 days compared to mOPV1 and bOPV1&3
      given at the standard interval of 30 days..

      The secondary endpoint is seroconversion following the birth dose of tOPV.

      All samples will be processed at the Centers of Disease Control and Prevention CDC)
      Laboratories (a Global Specialized Polio Network Laboratory).
    

Intervention name(s): mOPV1; bOPV 1,3
Intervention type(s): Drug; Drug
Intervention description(s): Monovalent type 1 oral poliovirus vaccine (mOPV1) containing at least106 TCID50 of Sabin- strain poliovirus type 1.; The bivalent vaccine containing at least 106 CCID50 of Sabin poliovirus type 1 and 105•8 CCID50 of Sabin poliovirus type 3.
Other intervention name(s): Monovalent type 1 oral poliovirus vaccine; Bivalent Oral Polio Vaccine
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Polio virus type 1,2,3; Poliovaccine-Oral; Poliovaccine; Trivalent Oral Polio vaccine; Monovalent oral polio vaccine; Bivalent Oral polio vaccine