Exploration of the biologic basis for underperformance of oral polio and rotavirus vaccines

1. Exploration of the biologic basis for underperformance of oral polio and rotavirus vaccines Progress to Date - Bangladesh Oral polio and rotavirus vaccines are significantly less effective in children living in the developing world compared to peers in other countries. Tropical enteropathy, which is associated with intestinal inflammation, decreased absorption and increased permeability, may contribute substantially to oral vaccine failure in developing country settings. The primary hypothesis of this clinical trial is that tropical enteropathy decreases the effectiveness of oral polio and rotavirus vaccines in infants by disrupting the enteric immune system. This single-blind study will enroll 1,070 healthy infants and their mothers residing in urban slums in Dhaka, Bangladesh and Kolkata, India in two prospective cohorts. The Bangladesh arm of the study, enrolling 700 infants from May 2011, will employ a 2x2 factorial study design, separately randomizing infants to receive oral rotavirus vaccine (Rotarix) and a boost of inactivated polio vaccine (IPV). The India arm of the study, enrolling 370 infants from early 2012, will randomize infants for a boost of IPV. The trial will investigate other possible causes of oral vaccine underperformance, including: malnutrition, interference with maternal or breast milk antibodies, changes in gut microbiota, and genetic susceptibility. Introduction Research Objectives Study Design Acknowledgements 2 x 2 Factorial Study Design (Bangladesh) Group A Rotarix + No IPV (175) Group B Rotarix + with IPV boost (175) Group C No Rotarix + No IPV (175) Group D No Rotarix + with IPV boost (175) This research is funded through the generous support of Bill and Melinda Gates Foundation. Primary Objective Determine whether decreased vaccine responsiveness to oral polio or rotavirus vaccines is associated with the presence of tropical enteropathy. Secondary Objectives Determine the impact of an inactivated polio vaccine (IPV) boost on systemic (neutralizing antibodies) and mucosal immune responses (shedding OPV vaccine virus) to polio vaccines following vaccination with oral polio vaccine (OPV). Determine the efficacy of rotavirus vaccination to prevent rotavirus diarrhea. Exploratory Objectives Describe the impact on vaccine failure and tropical enteropathy due to: • Breast milk and maternal antibodies • Malnutrition • Genetics (pending funding) • Changes in gut microbiome (Jeff Gordon) • Enteric Infections (Houpt: multiplex PCR) Devise novel cellular assays to explore immunologic phenotypes with vaccine failure and TE (Mark Davis, Stanford) • Phospho-flow (phosphorylation of STAT proteins) • Mass spec based flow cytometry (CyTOF) • Combinatorial tetramers with CyTOF • Gene expression Evaluate modified immunogenicity assays and biomarkers • ALS vs. ELISPOT • Breast milk IgA • Fecal IgA • Novel markers or indices of tropical enteropathy (with MAL-ED) Laboratory Progress Conducted extractions for fecal IgAanalysis on: Week 6 specimens 130 Week 17 specimens 19 Week 18 specimens 9 Shipped 252 stool specimens to the Bangladesh National Polio Lab for vaccine excretion analysis. Received preliminary results on 66 specimens. Processed 156 Week 6 blood specimens and 35 Week 18 blood specimens. Shipped 130 whole blood specimens to Children’s Hospital Oakland Research Institute for HLA analysis. Completed initial processing of 150 whole blood specimens for Phosphoflow analysis and shipped to Stanford University. Completed piloting of ALS assay for both rotavirus and polio. Methods Colgate ER, Kirkpatrick BD (University of Vermont); Haque R, Qadri F, Zaman K (ICDDR,B); Sur D (NICED); Czerkinsky C (IVI); Davis M (Stanford University); Gordon J (Washington University); Mychaleckyj J, Petri WA (University of Virginia) Clinical Progress since May 2011 Households surveilled 28,000+ Infants Screened 363 Infants Enrolled 215 (59% of screened) Adverse Events 16 Serious Adverse Events 6 Early Withdrawals 33 (15% of enrolled) Protocol Deviations 204 Specimen Collection Infant blood 2ml – 5ml Vaccine shedding stools Study visit stools Diarrheal stools Infant urine Mother blood Mother breast milk Clinic Procedures Gestational age assessment Anthropometry: child and mother Biweekly diarrhea surveillance Laboratory Assays Vaccine Immunogenicity • ALS or Elispot (Polio and Rotavirus) • Polio Plasma Neutralizing Antibody • Rotavirus Plasma IgA • Fecal excretion of vaccine virus • Fecal IgA • Fecal cytokines • Mother breast milk IgA Systemic Immunity • Tetanus IgG Exploratory Immunology • Phosphorylation of STAT proteins • Tetramer-flow cytometry • CyTOF mass spec based cellular analysis • Gene expression Tropical Enteropathy • Lactulose-Mannitol urine test • Plasma α-LPS and CRP Nutritional Status • Retinol, Vitamin D, Zinc, Ferritin HLA Microbiome Oral Polio Vaccine Efficacy2 Rotavirus Vaccine Efficacy1 Malnourished children (by HAZ) in Dhaka are more unresponsive to OPV. 1Parashar UD, Glass RI. Rotavirus vaccines--early success, remaining questions. N Engl J Med. Mar 12 2009;360(11):1063-1065. 2Petri, Snider, Pallansch, and Haque (unpublished)