Immunogenicity of a New Routine Vaccination Schedule for Global Poliomyelitis Prevention: An Open-Label, Randomized Controlled Trial

Conner Mansfield, Mercer University College of Pharmacy

The Global Polio Eradication Initiative Polio Eradication and Endgame Strategic Plan: 2013-2018 states that oral poliovirus vaccines (OPV) should be withdrawn in order to eliminate circulating vaccine-derived polioviruses.  The plan is to withdraw components from the vaccine sequentially starting with the type 2 component. The Global Polio Eradication Initiative intends to close gaps in immunity caused by the removal of these components with the administration of the inactivated poliovirus vaccine. [1]

Immunogenicity of a New Routine Vaccination Schedule for Global Poliomyelitis Prevention: An Open-Label, Randomized Controlled Trial [2]
Design Open-label, randomized, controlled trial; N= 900
Objective To assess the immunogenicity of a newly recommended sequential schedule of bivalent types 1 and 3 OPV (bOPV) and inactivated poliovirus vaccine (IPV)
Study Groups Trivalent OPV (tOPV) only, tOPV plus IPV, bOPV only, bOPV plus IPV, and bOPV plus two doses of IPV
Methods This study recruited full term neonates (born during the 37th week of gestation or after) weighing 2.5 kg or more. The study excluded neonates with a diagnosed or suspected medical disorder, a congenital defect that required medical management, an immunodeficiency disorder, or a coagulopathy. Patients received an OPV dose at birth, six weeks, 10 weeks, and 14 weeks. Patients receiving IPV received a dose with the OPV at week 14. Patients receiving two IPV doses received a dose with the OPV at week 14 and a dose at week 18. All patients received a challenge dose of tOPV at 18 weeks. Serum was collected at birth, 14 weeks, and at 18 weeks for all groups. An additional serum sample was taken at 22 weeks for groups receiving IPV and at 19 weeks for groups receiving bOPV plus two doses of IPV.
Duration Enrollment occurred between June 13 and August 29, 2013.
Primary Outcome Measure The immunogenicity of the new vaccine schedule compared with other vaccine regimens.
Baseline Characteristics   tOPV Only; n= 163 tOPV plus IPV; n= 153 bOPV; n= 155 bOPV plus IPV; n= 156 bOPV plus 2IPV; n= 155
Female Sex (%) 79 (48) 75 (49) 75 (48) 90 (58) 71 (46)
Median Birthweight—kg 2.9 2.8 2.9 2.8 2.8
Seropositive for Type 1 Poliovirus Antibodies (%) 135 (82.8) 127 (83.0) 127 (81.9) 126 (80.8) 121 (78.1)
Type 1 Median Reciprocal Titer 28 28 36 32 23
Seropositive for Type 2 Poliovirus Antibodies (%) 134 (82.2) 129 (84.3) 136 (87.7) 133 (85.3) 129 (83.2)
Type 2 Median Reciprocal Titer 28 28 28 28 23
Seropositive for Type 3 Poliovirus Antibodies (%) 96 (58.9) 99 (64.7) 96 (61.9) 89 (57.1) 81 (52.3)
Type 3 Median Reciprocal Titer 11 11 11 9 9
Results At Week 18 tOPV Only tOPV plus IPV bOPV bOPV plus IPV bOPV plus 2IPV
Seropositive for Type 1 Poliovirus Antibodies (%) 162 (99.4) 150 (98.0) 153 (98.7) 155 154
Type 1 Median Reciprocal Titer 724 910 1,152 ≥ 1,448 ≥ 1,448
Seropositive for Type 2 Poliovirus Antibodies (%) 157 (96.3) 153 (100) 29 (18.7) 107 121
Type 2 Median Reciprocal Titer 576 724 < 8 18 23
Seropositive for Type 3 Poliovirus Antibodies (%) 147 (90.2) 152 (99.3) 151 155 153
Type 3 Median Reciprocal Titer 228 455 362 910 910
Adverse Events Common Adverse Events: n= 128 (14.2%)
Serious Adverse Events: n= 12 (1.33%)
Percentage that Discontinued due to Adverse Events: Not reported
Study Author Conclusions The new schedule induces high levels of seroconversion and high-level mucosal immunity against poliovirus types 1 and 3, and as expected, a strong immunity base against poliovirus type 2.

This study demonstrates that a new poliovirus vaccine schedule using bOPV and IPV can be as immunogenic as previous OPVs against all three types of poliovirus. The data from this study support the use of this schedule in practice.

References

  1. Global Polio Eradication Initiative. Polio Eradication and Endgame Strategic Plan 2013–2018 Executive Summary. Geneva: World Health Organization, 2013. Available at: http://www.polioeradication.org/Portals/0/Document/Resources/StrategyWork/PEESP_ES_EN_A4.pdf.
  2. Sutter RW, Bahl S, Deshpande JM, et al. Immunogenicity of a new routine vaccination schedule for global poliomyelitis prevention: an open-label, randomised controlled trial. Lancet. 2015. Available at: http://www.ncbi.nlm.nih.gov/pubmed/26388534.

 

 

 

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