Muhammad Atif Habib1, Sajid Soofi1, Ondrej Mach2, Tariq Samejo1, Didar Alam1, Zaid Bhatti1, William C Weldon3, Steven M Oberste3, Roland Sutter2, Zulfiqar A Bhutta4. 1. Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan. 2. Polio Eradication Departments, World Health Organization, Geneva, Switzerland. 3. Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, USA. 4. Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan. Electronic address: Zulfiqar.bhutta@aku.edu.
Abstract
BACKGROUND: Considering the current polio situation Pakistan needs vaccine combinations to reach maximum population level immunity. The trial assessed whether inactivated poliovirus vaccine (IPV) can be used to rapidly boost immunity among children in Pakistan. METHODS: A five-arm randomized clinical trial was conducted among children (6-24months, 5-6years and 10-11years). Children were randomized in four intervention arms as per the vaccines they received (bOPV, IPV, bOPV+vitamin A, and bOPV+IPV) and a control arm which did not receive any vaccine. Baseline seroprevalence of poliovirus antibodies and serological immune response 28days after intervention were assessed. RESULTS: The baseline seroprevalence was high for all serotypes and the three age groups [PV1: 97%, 100%, 96%, PV2: 86%, 100%, 99%, PV3: 83%, 95%, 87% for the three age groups respectively]. There was significantly higher rate of immune response observed in the study arms which included IPV (95-99%) compared with bOPV only arms (11-43%), [p<0.001]; Vitamin A was not associated with improved immune response. Immune response rates in the IPV only arm and IPV+bOPV arm were similar [p>0.5]. CONCLUSION: IPV has shown the ability to efficiently close existing immunity gaps in a vulnerable population of children in rural Pakistan.
BACKGROUND: Considering the current polio situation Pakistan needs vaccine combinations to reach maximum population level immunity. The trial assessed whether inactivated poliovirus vaccine (IPV) can be used to rapidly boost immunity among children in Pakistan. METHODS: A five-arm randomized clinical trial was conducted among children (6-24months, 5-6years and 10-11years). Children were randomized in four intervention arms as per the vaccines they received (bOPV, IPV, bOPV+vitamin A, and bOPV+IPV) and a control arm which did not receive any vaccine. Baseline seroprevalence of poliovirus antibodies and serological immune response 28days after intervention were assessed. RESULTS: The baseline seroprevalence was high for all serotypes and the three age groups [PV1: 97%, 100%, 96%, PV2: 86%, 100%, 99%, PV3: 83%, 95%, 87% for the three age groups respectively]. There was significantly higher rate of immune response observed in the study arms which included IPV (95-99%) compared with bOPV only arms (11-43%), [p<0.001]; Vitamin A was not associated with improved immune response. Immune response rates in the IPV only arm and IPV+bOPV arm were similar [p>0.5]. CONCLUSION: IPV has shown the ability to efficiently close existing immunity gaps in a vulnerable population of children in rural Pakistan.
Authors: Arie Voorman; Muhammad Atif Habib; Imtiaz Hussain; Rana Muhammad Safdar; Jamal A Ahmed; William C Weldon; Imran Ahmed; Muhammad Umer; Jeffrey Partridge; Sajid Bashir Soofi Journal: Vaccine X Date: 2020-05-06