Immunogenicity and safety of Sabin strain-based inactivated poliovirus vaccine (sIPV) and typeⅠ+ Ⅲ bivalent oral poliovirus vaccine (bOPV) administered in different schedules / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To compare the safety and immunogenicity of Sabin strain-based inactivated poliovirus vaccine (sIPV) and the liquid form of typeⅠ+ Ⅲ bivalent oral poliovirus vaccine (bOPV) administered to infants aged ≥2 months in different schedules.Methods:A randomized, blinded, single-center, parallel-group controlled trial was conducted in Hangzhou from 2017 to 2018. Healthy infants aged ≥2 months were enrolled and randomized to receive the vaccines on a schedule of 2, 3, 4 months. Group 1sIPV+ 2bOPV was given one dose of sIPV and two doses of bOPV; group 2sIPV+ 1bOPV was administrated two doses of sIPV and one dose of bOPV; group 3sIPV received three doses of sIPV. Adverse events (AEs) following vaccination were recorded. Blood samples were collected from the subjects (excluding the quitters or subjects against the trial plan) 28-35 d after the full-course immunization. A microneutralization assay was performed to detect the geometric mean titers (GMTs) of neutralizing antibodies against polio virus of Ⅰ, Ⅱ and Ⅲ types. The seroconversion rates of neutralizing antibodies were also calculated.Results:The overall incidence of AEs following vaccination was 3.57% in 1sIPV+ 2bOPV group, 3.61% in 2sIPV+ 1bOPV group and 1.19% in 3sIPV group (χ 2=1.190, P=0.552) and no severe AEs were reported. The antibody seroconversion rates in 1sIPV+ 2bOPV, 2sIPV+ 1bOPV and 3sIPV groups were respectively 100% (84/84), 100% (83/83) and 100% (84/84) against type Ⅰ poliovirus, 81% (68/84), 96% (80/83) and 99% (83/84) against type Ⅱ poliovirus(χ 2=21.469, P<0.001), and 100% (84/84), 100% (83/84) and 100% (84/84) against type Ⅲ poliovirus. In 1sIPV+ 2bOPV, 2sIPV+ 1bOPV and 3sIPV groups, the GMTs of antibody were 1 024.00, 1 015.48 and 982.61 against type Ⅰ poliovirus ( F=2.742, P=0.066), 16.81, 107.94 and 218.85 against type Ⅱ poliovirus ( F=33.570, P<0.001), and 990.75, 990.36 and 613.92 against type Ⅲ poliovirus ( F=37.886, P<0.001). Conclusions:sIPV and bOPV administered in different schedules showed good safety and immunogenicity in infants aged≥2 months. The GMT and the seroconversion rate of neutralizing antibody against type Ⅱ poliovirus after vaccination were higher in 2sIPV+ 1bOPV and 3sIPV group than in 1sIPV+ 2bOPV group. Higher GMT of neutralizing antibody against type Ⅲ poliovirus was induced in 1sIPV+ 2bOPV and 2sIPV+ 1bOPV groups than in 3sIPV group.