Exploration of the Biologic Basis for Underperformance of Oral Polio and Rotavirus Vaccines in Bangladesh

Exploration of the Biologic Basis for Underperformance of Oral Polio and Rotavirus Vaccines in Bangladesh

Oral polio and rotavirus vaccines are significantly less effective in children living in the developing world. Tropical enteropathy, which is associated with intestinal inflammation, decreased absorption and increased permeability, may contribute substantially to oral vaccine failure in developing country settings. Other possible causes of oral vaccine underperformance include malnutrition, interference with maternal or breastmilk antibodies, changes in gut microbiota, and genetic susceptibility.

Primary Objective: to determine whether tropical enteropathy impairs the efficacy of oral polio and rotavirus vaccines in children in Bangladesh.

Secondary Objectives: 1) to determine the impact of an IPV (inactivated polio vaccine) boost on the efficacy of OPV (oral polio vaccine) and 2) to determine the efficacy of Rotarix oral rotavirus vaccine to prevent rotavirus diarrhea

The polio and rotavirus randomized clinical trials are embedded as secondary objectives within the exploratory study of tropical enteropathy. The primary and secondary outcome measures are relevant to the randomized clinical trials.

Inclusion Criteria:

1. Mother willing to sign informed consent form.
2. Healthy infant aged 0 to 7 days old.
3. No obvious congenital abnormalities or birth defects.
4. No abnormal (frequency and consistency) stools since birth.
5. Stable household with no plans to leave the area for the next one year.

Exclusion Criteria:

1. Parents are not willing to have child vaccinated at the field clinic.
2. Parents are not willing to have child's blood drawn.
3. Parents are planning to enroll child into another clinical study during the time period of this trial.
4. Mother not willing to have blood drawn and breast milk extracted.
5. Parents not willing to have field research assistant in home two times per week.
6. History of seizures or other apparent neurologic disorders.
7. Infant received any vaccines before start of study, except Bacillus Calmette-Guerin (BCG).
8. Infant has any sibling currently or previously enrolled in this study, including a twin.