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Immunogenicity of Different Routine Poliovirus Vaccination Schedules: A Randomized, Controlled Trial in Karachi, Pakistan.
- Source :
- Journal of Infectious Diseases; Feb2018, Vol. 217 Issue 3, p443-450, 8p
- Publication Year :
- 2018
-
Abstract
- <bold>Background: </bold>We assessed immunity against polioviruses induced with a new Pakistani poliovirus immunization schedule and compared it to alternative poliovirus immunization schedules.<bold>Methods: </bold>Newborns were randomized to undergo vaccination based on 1 of 5 vaccination schedules, with doses administered at birth and at 6, 10, and 14 weeks of age. Arm A received inactivated poliovirus vaccine (IPV) at all time points. Arm B received bivalent oral poliovirus vaccine (bOPV) at all time points. Arms C and D received bOPV at the first 3 time points and bOPV plus IPV at the final time point (the current schedule). Arm E received trivalent OPV (tOPV) at all time points. At 22 weeks of age, all children received 1 challenge dose of tOPV, and children in arm D received 1 additional IPV dose. Sera were analyzed for the presence of poliovirus neutralizing antibodies at birth and 14 and 22 weeks of age.<bold>Results: </bold>Seroconversion for poliovirus type 1 (PV1) at 22 weeks of age was observed in 80% of individuals in arm A, 97% in arm B, 94% in arm C, 96% in arm D, and 94% in arm E; for PV2, seroconversion frequencies were 84%, 19%, 53%, 49%, and 93%, respectively; and for PV3, seroconversion frequencies were 93%, 94%, 98%, 94%, and 85%, respectively.<bold>Conclusions: </bold>The current immunization schedule in Pakistan induced high seroconversion rates for PV1 and PV3; however, it induced PV2 seroconversion in only half of study subjects. There is a growing cohort of young children in Pakistan who are unprotected against PV2; and this creates an increasing risk of a large-scale outbreak of poliomyelitis caused by circulating vaccine-derived PV2. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00221899
- Volume :
- 217
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Journal of Infectious Diseases
- Publication Type :
- Academic Journal
- Accession number :
- 127440680
- Full Text :
- https://doi.org/10.1093/infdis/jix577