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The Effects of Increased Inoculum on Oral Rotavirus Vaccine Take and Immunogenicity

Phase 4
Completed
Conditions
Vaccine Virus Shedding
Vaccine Response Impaired
Rotavirus Infection
Interventions
Biological: Rotarix, dose 1
Biological: Rotarix, dose 2
Drug: Placebo (for Rotarix dose 2)
Registration Number
NCT02992197
Lead Sponsor
University of Vermont
Brief Summary

Rotavirus is the leading cause of diarrhea in children worldwide. Oral rotavirus vaccines work remarkably well in high-income countries, but for unclear reasons they underperform in low-income countries. A double-blind, randomized control trial will be performed to evaluate whether using a higher dose of a currently licensed vaccine (Rotarix, GlaxoSmithKline) can improve immune responses among infants in Dhaka, Bangladesh.

Infants will be randomized 1:1 to receive either a standard or a double dose of Rotarix at 6 and 10 weeks of life. Infants will be assessed for fecal vaccine shedding and serum rotavirus-specific IgA responses to determine vaccine immunogenicity.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
220
Inclusion Criteria
  1. Generally healthy infant (as determined by medical officers)
  2. Age 0-7 days at enrolment
  3. Mother willing and able to provide signed informed consent
  4. Mother willing to allow infant to be vaccinated according to study schedule
  5. Mother willing to allow biological specimens, including blood, stool, and saliva, to be collected from infant according to study protocol
  6. Mother willing and able to adhere to study schedule
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Exclusion Criteria
  1. Obvious congenital malformation
  2. Birth weight (if known) or enrolment weight (if birth weight unknown) < 2000 gm
  3. Known immunocompromising condition in infant
  4. Enrolment in other vaccine research trials
  5. Other household member enrolled in this study
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Rotarix, single doseRotarix, dose 1Rotarix 1.5 mL (standard single dose) and 1.5 mL of placebo by mouth (sterile, pharmacy-grade water) at both 6 and 10 weeks of life
Rotarix, double doseRotarix, dose 2Rotarix 3 mL by mouth (two standard doses administered simultaneously) at both 6 and 10 weeks of life
Rotarix, double doseRotarix, dose 1Rotarix 3 mL by mouth (two standard doses administered simultaneously) at both 6 and 10 weeks of life
Rotarix, single dosePlacebo (for Rotarix dose 2)Rotarix 1.5 mL (standard single dose) and 1.5 mL of placebo by mouth (sterile, pharmacy-grade water) at both 6 and 10 weeks of life
Primary Outcome Measures
NameTimeMethod
Number (or Percentage) of Infants in Each Study Arm With Rotavirus-specific Plasma Immunoglobulin A (IgA) Seroconversion Post-vaccinationMeasured at week 14 of life

This outcome will measure seroconversion, i.e. the change in plasma rotavirus-specific IgA concentration at week 14 of life compared to week 6 of life (baseline). Blood will be collected from infants prior to the first dose of Rotarix at week 6 of life and again at week 14 of life (4 weeks following the second dose) for measurement of plasma rotavirus-specific IgA by enzyme immunoassay. Infants will be assessed for seroconversion (IgA concentration \<=20 U/mL pre-vaccination and \>20 post-vaccination). Infants who demonstrate rotavirus-specific IgA seroconversion will be categorized as having met the outcome measure.

Number (or Percentage) of Infants in Each Study Arm With Successful Vaccine Take, Defined as Positive Fecal Vaccine Shedding Post-vaccination OR Rotavirus-specific Plasma IgA Seroconversion Post-vaccinationMeasured at week 14 of life

Vaccine take is an aggregate, dichotomous immunogenicity measure (successful vaccine take vs no vaccine take). Infants positive for either fecal vaccine shedding OR plasma rotavirus-specific IgA seroconversion (as described in Outcomes 1 and 2, respectively) will be categorized as having met the outcome measure of successful vaccine take. Those who met neither outcome will be categorized as no vaccine take.

Number (or Percentage) of Infants in Each Study Arm Who Test Positive for Fecal Rotavirus Vaccine-strain Virus Shedding Post-vaccinationMeasured through week 12 of life

This will be an aggregate measure demonstrating a change from baseline. Infants will have stool collected immediately prior to Rotarix vaccination at weeks 6 and 10 of life, then 4, 7, and 14 days following each dose (i.e. last assessment at week 12 of life). Each specimen will be assessed for vaccine-strain virus (i.e. fecal vaccine shedding) at each time point by polymerase chain reaction. Any child who has a change in fecal vaccine shedding status, from negative at baseline (6 weeks) to positive at any subsequent time point, will be categorized as having met the outcome measure for positive fecal vaccine shedding.

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b)

🇧🇩

Dhaka, Bangladesh

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