Duration of IPV Priming and Antibody Decay
Condition: Poliomyelitis
MeSH terms: Poliomyelitis
Study type: Interventional
Phase: Phase 4

Summary: 
      This is an open-label randomized phase IV clinical trial assessing immunogenicity of
      poliovirus vaccines.Participants will be enrolled at 6 weeks of age and followed to 18 months
      of age. The study will recruit 1645 participants in five arms.
    

Detailed description: 
      Poliomyelitis is an acute infection caused by polioviruses. Oral poliovirus vaccines are live
      attenuated viral vaccines and the vaccine virus in OPV can mutate and acquire neurovirulence
      causing paralysis either due to vaccine-associated paralytic polio (VAPP) or due to
      circulating vaccine-derived polioviruses (cVDPV), in which the attenuated vaccine virus not
      only acquires the ability to cause paralysis but can also circulate similar to wild
      poliovirus (WPV). Therefore, polio eradication will require eventual cessation of all OPVs.

      Wild poliovirus type 2 (WPV2) was declared eradicated in September 2015. Since then paralysis
      associated with type 2 poliovirus has continued mainly due to vaccine derived polio viruses
      (VDPVs) from type 2 OPV (OPV2). Due to the continued threat of paralysis from a mutated,
      neurovirulent and vaccine-derived type 2 poliovirus, the Strategic Advisory Group of Experts
      on Immunization (SAGE), a global advisory committee on immunization, recommended a phased
      cessation of OPV starting with OPV2. By May 2016, OPV2 was successfully withdrawn globally
      when trivalent OPV (tOPV) was replaced with bivalent OPV (bOPV), which was preceded by a
      phased introduction of inactivated poliovirus vaccine (IPV). SAGE has recommended at least
      one dose of IPV at age ≥14 weeks because IPV immunogenicity is expected to be highest after
      maternal antibodies have declined by age 14 weeks. However, studies have not assessed if
      priming after one IPV dose declines over time.

      Types 1 and 3 OPV cessation is likely expected in 2020-2022, i.e. 1-2 years after
      certification of global interruption of wild poliovirus transmission. After cessation of
      bOPV, IPV will be used for routine polio vaccination for 5-10 years.Recently, SAGE
      recommended that IPV be used after global OPV withdrawal with an IPV schedule that achieves
      at least 90% seroconversion with two full or fractional doses. SAGE has recommended that the
      first dose be administered after 14 weeks of age and an interval of at least 4 months between
      two IPV doses. In the proposed clinical trial, immunogenicity of two IPV doses with schedules
      that are likely to achieve 90% immune response to all poliovirus types is being assessed to
      inform SAGE policy deliberations on potential IPV schedules after OPV cessation. A
      head-to-head comparison of different IPV schedules is important to determine the
      immunogenicity of the schedules under similar conditions and evaluate the differences in
      population immunity, a product of immunogenicity and vaccination coverage, with the different
      IPV schedules.
    

Intervention name(s): Bivalent oral poliovirus vaccine (bOPV) at 6,10 and 14 weeks of age; Inactivated poliovirus vaccine (IPV) at 14 weeks and 18 months of age; Inactivated poliovirus vaccine (IPV) at 14 weeks, 18 weeks and 18 months of age; Inactivated poliovirus vaccine (IPV) at 14 weeks and 9 months of age; Inactivated poliovirus vaccine (IPV) at 6 weeks and 9 months of age; Inactivated poliovirus vaccine (IPV) at 6 and 14 weeks of age
Intervention type(s): Biological; Biological; Biological; Biological; Biological; Biological
Intervention description(s): bOPV at 6, 10 and 14 weeks of age; IPV at 14 weeks and 18 months of age; IPV at 14 weeks, 18 weeks and 18 months of age; IPV at 14 weeks and 9 months of age; IPV at 6 weeks and 9 months of age; IPV at 6 and 14 weeks of age
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Inactivated polio vaccine; Polio; oral polio vaccine