To Evaluate the Immunogenicity and Safety of Sequential Immunization Schedules of Sabin IPV and bOPV

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to evaluate the immunogenicity and safety of sequential immunization schedules of Sabin IPV and bOPV.

Detailed Description
-----------------
A phase 4 clinical trial is designed to evaluate the safety and immunogenicity of different sequential immunization schedules of Sabin IPV and bOPV. To be specific, the subjects were divided into 3 groups. Group 1 received Sabin-IPV+bOPV+bOPV respectively at the age of 2,3,4 months old. Group 2 received Sabin-IPV+Sabin-IPV+bOPV respectively at the age of 2,3,4 months old. Group 3 received Sabin-IPV+Sabin-IPV+Sabin-IPV respectively at the age of 2,3,4 months old. Blood samples were collected before vaccination and 30 days after the third dose. Neutralization antibody against type I, Type II and Type III poliomyelitis virus were detected to evaluate the seroprotection rates and antibody geometric mean concentrations. The safety of the 3 immunization schedule groups were also monitored.

Official Title
-----------------
A Randomized, Multi-center, Controlled Clinical Trial for Evaluating the Immunogenicity and Safety of Sequential Immunization Schedules of Sabin IPV and bOPV

Conditions
-----------------
Vaccination, Reaction - Vaccine

Intervention / Treatment
-----------------
* Biological: Sabin-IPV+bOPV+bOPV
* Biological: Sabin-IPV+Sabin-IPV+bOPV
* Biological: Sabin-IPV+Sabin-IPV+Sabin-IPV


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: subjects aged from 60 days to 89 days old at the date of recruitment; with informed consent signed by parent(s) or guardians; parent(s) or guardians are able to attend all planned clinical appointments and obey and follow all study instructions; subjects did not receive any vaccination within 14 days; axillary temperature ≤37.0℃ Exclusion Criteria: allergic to any ingredient of vaccine or with allergy history to any vaccine; acute febrile disease or infectious disease; serious chronic diseases; any other factor that makes the investigator determines the subject is unsuitable for this study;

Ages Eligible for Study
-----------------
Minimum Age: 60 Days
Maximum Age: 89 Days

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: sIPV+bOPV+bOPV<br>202 subjects were vaccinated with 1 dose of Sabin-IPV and 2 doses of bOPV at their age of 2/3/4 months old, respectively | Biological: Sabin-IPV+bOPV+bOPV<br>* 202 subjects were vaccinated with 1 dose of Sabin-IPV and 2 doses of bOPV at their age of 2/3/4 months old, respectively<br>|
| Active Comparator: sIPV+sIPV+bOPV<br>197 subjects were vaccinated with 2 doses of Sabin-IPV and 1 dose of bOPV at their age of 2/3/4 months old, respectively | Biological: Sabin-IPV+Sabin-IPV+bOPV<br>* 197 subjects were vaccinated with 2 doses of Sabin-IPV and 1 dose of bOPV at their age of 2/3/4 months old, respectively<br>|
| Active Comparator: sIPV+sIPV+sIPV<br>205 subjects were vaccinated with 3 doses of Sabin-IPV at their age of 2/3/4 months old, respectively | Biological: Sabin-IPV+Sabin-IPV+Sabin-IPV<br>* 205 subjects were vaccinated with 3 doses of Sabin-IPV at their age of 2/3/4 months old, respectively<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Seroconversion rates at both baseline and 30 days after the 3rd vaccination | Determine the seroconversion rates of poliovirus (types I,II,III）at both baseline and 30 days after the 3rd vaccination | 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neutralizing antibody titers at both baseline and 30 days after the 3rd vaccination | Measure neutralizing antibody titers against poliovirus type I, II and III at both baseline and 30 days after the 3rd vaccination | 4 months |