[Effectiveness of inactivated poliomyelitis vaccine for primary vaccination].
OBJECTIVE
To study the immunological effectiveness of inactivated poliomyelitis vaccine (IPV) for children's primary vaccination in China and to compare with the oral poliomyelitis vaccine (OPV) used in routine vaccination.


METHODS
The 2-month-old children were randomly immunized with IPV and OPV, with 208 subjects in each group. The pre- and post-vaccination blood samples were collected. Micro-neutralization method was used to measure the antibody response against 3 types of polioviruses. chi2 test was used to evaluate the statistical difference of protection rates between two groups, while the antibody titers were transformed by logarithm and analyzed by Z-test. P < 0.05 was always used to define the significance of analysis.


RESULTS
After 3 doses of immunization, the protection rates in IPV group reached to 100.0% (186/186), 97.3% (181/186), 98.9% (184/186) for poliovirus type 1, 2, 3, respectively, and in OPV group were 97.4% (188/193), 100.0% (193/193), 95.3% (184/193), respectively. The geometry mean titers (GMTs) were 151.2, 86.7, 211.3 for IPV group; and 1089.5, 538.2, 203.7 for OPV group. IPV showed comparable protection rates with OPV for type 1 and 2 (chi2(I) = 2.991, P = 0.084; chi2(II) = 3.512, P = 0.061), while type 3 was higher than OPV (chi2(III) = 4.143, P = 0.042). The GMT of type 1 and 2 in IPV group were lower than OPV group (Z(I) = 12.537, P = 0.000; Z(II) = 13.415, P = 0.000), while the GMT of type 3 were comparable in two groups (Z(III) = 0.067, P = 0.947).


CONCLUSIONS
IPV showed roughly comparable immunological effectiveness in young children. The protection rates for type 1 and 2 were similar to OPV, while type 3 was higher than in OPV group; In terms of GMT,type 1 and 2 in IPV group were lower than OPV, but type 3 were comparable to OPV group.
Li
Chang-Gui
CG
National Institute for the Control of Pharmaceutical and Biological Products, Beijing 100050, China.
Ying
Zhi-Fang
ZF
Wang
Jian-Feng
JF
Fang
Han-Hua
HH
Li
Yan-Ping
YP
Li
Rong-Cheng
RC
Bonnet
Marie-Claude
MC
Zhang
Yan-Ping
YP
D000914:Antibodies, Viral / Q000097:blood; D006801:Humans; D007223:Infant; D011051:Poliomyelitis / Q000517:prevention & control*; D011054:Poliovirus Vaccine, Inactivated / Q000276:immunology*; D011055:Poliovirus Vaccine, Oral / Q000276:immunology*
D000914:Antibodies, Viral; D011054:Poliovirus Vaccine, Inactivated; D011055:Poliovirus Vaccine, Oral