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

A Double-blind, Randomized Controlled Trial of the Effect of Vaccine Inoculum on Oral Rotavirus Vaccine (Rotarix, GlaxoSmithKline) Take and Immunogenicity in Dhaka, Bangladesh

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.

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

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