Effect of booster doses of poliovirus vaccine in previously vaccinated children, Clinical Trial Results 2013.
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.



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.



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].



IPV has shown the ability to efficiently close existing immunity gaps in a vulnerable population of children in rural Pakistan.
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Muhammad Atif
MA
Habib
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Sajid
S
Soofi
Polio Eradication Departments, World Health Organization, Geneva, Switzerland.
Ondrej
O
Mach
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Tariq
T
Samejo
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Didar
D
Alam
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Zaid
Z
Bhatti
Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, USA.
William C
WC
Weldon
Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, USA.
Steven M
SM
Oberste
Polio Eradication Departments, World Health Organization, Geneva, Switzerland.
Roland
R
Sutter
Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan. Electronic address: Zulfiqar.bhutta@aku.edu.
Zulfiqar A
ZA
Bhutta
D000914:Antibodies, Viral; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D056724:Immunity, Humoral; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D010154:Pakistan; D011051:Poliomyelitis / Q000517:prevention & control*; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage / Q000627:therapeutic use*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage / Q000627:therapeutic use; D016036:Seroepidemiologic Studies; D065288:Serogroup; D014801:Vitamin A / Q000008:administration & dosage
D000914:Antibodies, Viral; D011054:Poliovirus Vaccine, Inactivated; D011055:Poliovirus Vaccine, Oral; D014801:Vitamin A
Immunity; Injectable polio vaccine; Pakistan; Polio virus vaccine; Seroconversion; Seroprevalence