title: [Study of immunogenicity after primary vaccination by different sequential program of inactivated poliovirus vaccine and oral poliovirus vaccine].
abstract: OBJECTIVE
  To evaluate immunogenicity after primary vaccination by different sequential program of inactivated poliovirus vaccine (IPV) and oral poliovirus vaccine (OPV).
  
  
  METHODS
  Children of 2 months old (60-89 days) selected in Beijing were assigned to 4 groups, 1 dose IPV plus 2 doses OPV (I-O-O, 122 children), 2 doses IPV plus 1 dose OPV(I-I-O, 103 children), 3 doses IPV (I-I-I, 114 children), and 3 doses OPV (O-O-O, 106 children), and were vaccinated at the age of 2, 3, 4 months. Polio neutralizing antibody titers against poliovirus types 1, 2, and 3 were tested and protective rates were calculated before the 1st dose, after the last dose, and after the 1st and 2nd dose of IPV.
  
  
  RESULTS
  After the primary immunization, geometric mean titers (GMT) of polio neutralizing antibody titers against poliovirus types 1, 2, and 3 were 788.32, 738.42 and 631.17 in O-O-O group, 212.02, 262.30 and 537.52 in I-I-I group, 940.35, 929.72 and 940.35 in I-O-O group and 901.09, 1102.68 and 1110.12 in I-I-O group (F values were 47.71, 53.84, and 9.81 respectively, all P values<0.01). The protective rate of three types among each group was 98.1% (104/106)-100.0% and the difference was not statistically significant (P>0.05). After the 1(st) dose of IPV, the GMT were 18.88, 37.77, 24.64 and the protective rate was 82.6% (122/138)-96.4% (133/138); after the 2nd dose of IPV, GMT were 177.03, 168.25, 321.86 and the protective rate was 99.1% (108/109)-100.0% (109/109) in antibody types 1, 2 and 3, respectively.
  
  
  CONCLUSIONS
  GMT of polio neutralizing antibody titers against poliovirus is higher after vaccination by sequential program of IPV and OPV than that by IPV or OPV 3-doses program. High level of protective rate after 2 doses of IPV in I-I-O group may lead to better protection from vaccine associated paralytic poliomyelitis (VAPP). Sequential program of IPV and OPV can be used to maintain high level of herd immunity and to prevent VAPP, and the I-I-O sequential program should be the first choice.
authors.affiliation: Department of Immunization, Beijing Centre for Disease Control and Prevention, Beijing 100013, China. lulibj@sina.com
authors.forename: Li
authors.initials: L
authors.lastname: Lu
authors.forename: Xiao-mei
authors.initials: XM
authors.lastname: Li
authors.forename: Dong-lei
authors.initials: DL
authors.lastname: Liu
authors.forename: He-run
authors.initials: HR
authors.lastname: Zhang
authors.forename: Zhu-jia-zi
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: Hai-hong
authors.initials: HH
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Zhao-qi
authors.initials: ZQ
authors.lastname: Ning
authors.forename: Li-wen
authors.initials: LW
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Chu
authors.forename: Yan-tao
authors.initials: YT
authors.lastname: Xie
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Xing-huo
authors.initials: XH
authors.lastname: Pang
authors.forename: Ying
authors.initials: Y
authors.lastname: Deng
mesh_terms: D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage / Q000276:immunology*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000276:immunology*
chemical_list: D011054:Poliovirus Vaccine, Inactivated; D011055:Poliovirus Vaccine, Oral; D014613:Vaccines, Attenuated