The Evaluation On The Efficacy And Safety Of Sequential Immunization With Domestic Polio Vaccine

Objective:The purpose of this study was to investigate the immune effect of sequential immunization with domestic inactivated poliovirus vaccine and oral poliomyelitis attenuated Live Vaccine,and to evaluate the safety of inactivated poliovirus vaccine,so as to provide the evidence to adjust the mmunization strategy of poliomyelitis vaccine in china.Part 1 The Evaluation on the Efficacy of Sequential Immunization with Domestic Polio VaccineMethods:More than 180 two month old healthy children in Tongxin County of Ningxia were selected into a non-randomized controlled experimental study during the period from September to December in 2015.The children were vaccinated at two,three and four months respectively according to the procedure of the national immunization program.They were divided into two groups,one group of children were performed with tOPV+tOPV+tOPV(O-O-O group),which called basic immunization program,the other group were performed with IPV(Sabin)+ tOPV +tOPV(I-O-O group)which called sequential immunization program.Serum samples were collected from the same recipients before and after 30 days of vaccination with 1 or 2 or 3 doses of polio vaccine.Ⅰ,Ⅱ and Ⅲ antibody levels in serum were detected by micro neutralization test.Then the Geometric antibody titer,positive rate and protection rate were calculated.Results:1.There was significant difference between two groups before and after immunization in all types of poliomyelitis antibody titer(P﹤0.05).After the inmmuzation,the antibody titers of three types were higher than those before immunization.2.Compared with O-O-O group,the Ⅱ and Ⅲ antibody titer of IPV(Sabin)group was lower than that of tOPV group after 1 doses of polio vaccine,there was no significant difference among the antibody titer of 3 types after 2 doses of polio vaccine,but Ⅱ and Ⅲ type antibody titers in I-O-O group were higher than those in O-O-Ogroup after 3 doses of polio vaccine.3.Compared with O-O-O group,in group IPV(Sabin),the positive rates of Ⅱ and Ⅲ type poliomyelitis antibody were lower than those of group tOPV after 1 doses of polio vaccine,in IPV(Sabin)+tOPV group,the positive rate of Ⅱ type antibody was lower than that of tOPV+tOPV group after 2 doses of polio vaccine,there was no significant difference between the I-O-O group and the O-O-O group in the positive rate of the antibody of poliomyelitis after 3 doses of polio vaccine(P﹥0.05),which were all above 89%.4.There was no significant difference between the I-O-O group and the O-O-O group in the protective rate of poliomyelitis after 3 doses of polio vaccine(P﹥0.05),which were all above 96%.Conclusion:After 3 doses of polio vaccine,In I-O-O group,the titer of Ⅱ and Ⅲ type,s antibody of poliomyelitis were higher than the O-O-O group,the positive rates and protective rates of 3 types of poliomyelitis antibody were all high in both groups.Domestic IPV and tOPV sequential immunization program can provide similar or even higher immune protection against poliovirus compared to the whole tOPV.Part2 The Evaluation on the Safety of Domestic Inactivated Poliomyelitis VaccineMethods:Active surveillance and passive surveillance were adopted to evaluate the safety of the vaccine by calculating the occurrence of adverse events following immunization.Active surveillance:During the period from September 2015 to February 2016,children vaccinated with domestic IPV(Sabin)and tOPV in Tongxin county were investigated at a specific time after vaccination,to investigate the incidence of adverse reactions after vaccination.Passive surveillance: The data was collected from China information management system for immunization programming from 2008 to 2016 in Ningxia,by calculating the incidence of adverse reactions to analyze the safety.Results:1.The active surveillance results showed that the incidence of general reaction of IPV(Sabin)was 246.4/10,000,and the incidence of tOPV was 64.92/100,000.Although the incidence of IPV(Sabin)was higher than tOPV,but no serious abnormal reaction occurred.2.The passive surveillance results showed that the incidence of general reaction of IPV(Sabin)was 51.68/100,000,and the incidence of abnormal reaction of IPV(Sabin)was1.67/100,000.The incidence of general reaction of tOPV was 1.73/100,000,and the incidence of abnormal reaction of tOPV was 0.22/100,000,which was lower than IPV(Sabin).3.Compared with other EPI Vaccines,although the incidence of general reaction of IPV(Sabin)was higher,but the abnormal reaction rate was lower than measles vaccine,diphtheria vaccine,MMR and BCG,and no serious abnormal reaction occurred.Conclusion:The sensitivity of active surveillance was higher than passive surveillance in adverse events following immunization,there was no serious abnormal reaction after vaccination with domestic IPV(Sabin),and it was one of the safer vaccines in the national immunization program.