Anand Abhijeet, Zaman K, Estívariz Concepción F, Yunus Mohammad, Gary Howard E, Weldon William C, Bari Tajul I, Steven Oberste M, Wassilak Steven G, Luby Stephen P, Heffelfinger James D, Pallansch Mark A
Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30033, United States.
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Sarani, Dhaka 1212, Bangladesh.
Vaccine. 2015 Nov 27;33(48):6816-22. doi: 10.1016/j.vaccine.2015.09.039. Epub 2015 Oct 23.
Inactivated poliovirus vaccine (IPV) introduction and phased oral poliovirus vaccine (OPV) cessation are essential for eradication of polio.
Healthy 6-week old infants in Bangladesh were randomized to one of five study arms: receipt of trivalent OPV (tOPV) or bivalent OPV (bOPV) at ages 6, 10 and 14 weeks, intramuscular IPV or intradermal one-fifth fractional dose IPV (f-IPV) at ages 6 and 14 weeks, or f-IPV at ages 6 and 14 weeks with bOPV at age 10 weeks (f-IPV/bOPV). All participants received tOPV at age 18 weeks.
Of 975 infants randomized, 95% (922) completed follow-up. Type 1 seroconversion after 3 doses at 6, 10 and 14 weeks was higher with bOPV compared with tOPV (99% vs 94%, p=0.019). Seroconversions to types 1 and 3 after 2 IPV doses at ages 6 and 14 weeks were no different than after 3 doses of tOPV or bOPV at ages 6, 10 and 14 weeks. A priming response, seroconversion 1 week after IPV at 14 weeks among those who did not seroconvert after IPV at 6 weeks, was observed against poliovirus types 1, 2 and 3 in 91%, 84% and 97%, respectively. Compared with IPV, f-IPV failed non-inferiority tests for seroconversion with 1 or 2 doses and priming after 1 dose.
The findings demonstrate considerable priming with IPV at age 6 weeks, comparable immunogenicity of tOPV and bOPV, and inferior immunogenicity of one-fifth f-IPV compared with IPV. If IPV induced priming at age 6 weeks is similar to that at age 14 weeks, IPV could be administered at a younger age and possibly with a higher coverage.
引入灭活脊髓灰质炎病毒疫苗（IPV）并分阶段停用口服脊髓灰质炎病毒疫苗（OPV）对于根除脊髓灰质炎至关重要。
孟加拉国健康的6周龄婴儿被随机分为五个研究组之一：在6、10和14周龄时接种三价OPV（tOPV）或二价OPV（bOPV），在6和14周龄时接种肌内注射IPV或皮内注射五分之一剂量IPV（f-IPV），或在6和14周龄时接种f-IPV并在10周龄时接种bOPV（f-IPV/bOPV）。所有参与者在18周龄时接种tOPV。
在随机分组的975名婴儿中，95%（922名）完成了随访。在6、10和14周龄接种3剂后，bOPV诱导的1型血清阳转率高于tOPV（99%对94%，p=0.019）。在6和14周龄接种2剂IPV后，1型和3型的血清阳转率与在6、10和14周龄接种3剂tOPV或bOPV后的血清阳转率没有差异。在6周龄接种IPV后未发生血清阳转的婴儿中，观察到在14周龄接种IPV后1周出现的针对脊髓灰质炎病毒1、2和3型的激发反应，血清阳转率分别为91%、84%和97%。与IPV相比，f-IPV在接种1剂或2剂后的血清阳转以及接种1剂后的激发反应方面未通过非劣效性检验。
研究结果表明，6周龄时IPV具有显著的激发作用，tOPV和bOPV的免疫原性相当，且与IPV相比，五分之一剂量的f-IPV免疫原性较差。如果6周龄时IPV诱导的激发作用与14周龄时相似，IPV可以在更小年龄接种，并且可能具有更高的覆盖率。
