Immunogenicity of Rotavirus Vaccine

The Immunogenicity of Rotavirus Vaccine Under Different Age Schedules and the Impact of Withholding Breast Feeding Around the Time of Vaccination on the Immunogenicity of Rotarix Vaccine

Rotavirus is one of the most common causes of severe diarrhea, responsible for 40% of all diarrhea related deaths in children worldwide. Two vaccines against Rotavirus, Rotarix® and Rotateq® were licensed in many high and middle income countries in 2006, but lack of efficacy data in low income countries had prevented WHO from making a universal recommendation of their use until recently. This study will be conducted in Pakistan and will look at two objectives:

1. To compare the immunogenicity of Rotarix® vaccine when administered at 6 and 10 weeks of life and at 6, 10 and 14 weeks of life.
2. To compare the immunogenicity of Rotarix® vaccine in infants breast fed at the time of vaccine administration with infants whose breast feeding is withheld for one hour before and after vaccine administration.

Inclusion Criteria:

• 6 weeks 0 days to 6 weeks 6 days age at the time of enrollment.
• Healthy infant free of chronic or serious medical condition as determined by history and physical exam at time of enrollment into in the study.
• Written informed consent obtained from the parents or guardians.

Exclusion Criteria:

• Hypersensitivity to any of the vaccine components.
• Use of any investigational drug or vaccine other than the study vaccine within 30 days of first dose of study vaccine or during the study.
• Use of any immunosuppressive drugs.
• Previous intussusception or abdominal surgery.
• Enrolment in any other trial (Simplified Antibiotic Therapy for Neonatal Sepsis Trial, Management of Omphalitis Trial).
• Birth weight less than 1500 grams; or if birth weight is unknown, weight less than 2000 grams on or before 28 days.
• Immunoglobulin and/or blood products use since birth or during the study period.