A Study to Evaluate the Safety and Immunogenicity of Oral Polio Vaccine Type 2 in Infants and Children
Condition: Adverse Event Following Immunisation
Study type: Interventional
Phase: Phase 4

Summary: 
      Sabin 2 will be withdrawn from routine use globally from April 2016 as per the SAGE
      recommendations at the time of writing this protocol. After this cessation of OPV2,
      stockpiles of mOPV2 will be maintained for potential use if necessary in response to a future
      outbreak. However, there will be a risk of cVDPV2 from Sabin 2 in settings of low population
      immunity. Research is ongoing to develop vaccines that are genetically more stable than the
      currently available Sabin 2-containing OPVs. To generate data on immunogenicity, safety, and
      genetic stability on the Sabin 2 vaccine (mOPV2) and as a future comparator for new polio
      vaccine research after the global switch from tOPV to bOPV, this study with mOPV2 is
      performed to evaluate safety, immunogenicity (humoral and intestinal) and genetic stability
      endpoints of mOPV2 in children aged 1 to 5 years and in infants approximately 18 weeks of
      aged vaccinated with bOPV-/IPV for better understanding of the stockpile use of this vaccine,
      and for comparison with any potential new polio vaccine with a type 2 component in the
      future.
    

Detailed description: 
      1. PRIMARY OBJECTIVE The primary objectives of the study are to assess the safety (serious
           adverse events [SAEs] and severe adverse events [AEs] grade 3 according to CTCAE 4.03
           and immunogenicity (seroprotection rate) of a single dose of SABIN mOPV2 in healthy
           children aged 1 to 5 years old, and in infants at approximately 18 weeks of age after
           having been vaccinated with 3 doses of bOPV and 1 dose of IPV .

        2. SECONDARY OBJECTIVES

           Secondary objectives are to assess:

             -  The safety (mild and moderate solicited and unsolicited AEs, Important Medical
                Events [IMEs], and laboratory deviation assessments) of one or two doses of SABIN
                mOPV2 in healthy children aged 1 to 5 years, and of 2 doses of SABIN mOPV2 in
                infants at approximately 18 and 22 weeks of age after having been vaccinated with 3
                doses of bOPV and 1 dose of IPV.

             -  The immunogenicity (seroconversion rate, median and geometric mean antibody titers)
                of one or two doses of SABIN mOPV2 in healthy children aged 1 to 5 years old, and
                of two doses of SABIN mOPV2 in infants at approximately 18 22 weeks of age after
                having been vaccinated with 3 doses of bOPV and 1 dose of IPV.

        3. EXPLORATORY OBJECTIVES

      Exploratory objectives are:

        -  To investigate viral shedding following the SABIN mOPV2 administration.

        -  Exploratory objectives may also include assessment of the genetic sequence heterogeneity
           and potential for neurovirulence (as measured in animal model(s)) of shed virus.

        -  To investigate viral shedding and neurovirulence of shed virus;

        -  To evaluate genetic reversion at position nt481 (primarily) and other secondary sites
           (e.g., nt2908).

        -  To investigate the priming responses of bOPV for mOPV2. (group 2 only) and the duration
           of induction of anti-polio type 2 neutralizing antibodies .
    

Intervention name(s): SABIN monovalent OPV2
Intervention type(s): Biological
Intervention description(s): SABIN monovalent OPV2 is a licensed, monovalent, live attenuated poliomyelitis virus vaccine of the Sabin strain Type 2 (P 712, Ch, 2ab), propagated in MRC5 human diploid cells. Each two-drop dose (0.1 mL) contains not less than 105.0 CCID50 of Type 2
Other intervention name(s): Polio Sabin™ Mono Two (oral)
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention