Rubella Syndrome, Congenital clinical trials

Measles-Rubella Vaccine Immunogenicity at 6 and 9 Months of Age

This is an open-label, randomized, 2-arm clinical trial in healthy infants in Bangladesh. The primary purpose of the study is to assess the immunogenicity of measles-rubella (MR) vaccine when delivered at 6 months. In addition, the study will establish the equality of MR vaccine seroconversion administered at 9 months following administration of an earlier MR vaccine dose at 6 months of age compared to MR vaccine dose administered at 9 months without previous MR vaccination. This study will also provide additional data on safety and tolerance of MR vaccine given at 6 months, and impact of maternal antibodies on immunogenicity of MR vaccine at 6 months. - Primary objectives: 1. To assess immunogenicity of MR vaccine at 6 months of age 2. To assess immunogenicity of MR vaccine at 9 months of age among children without prior measles and rubella vaccination, compared with MR vaccine immunogenicity among those who had a prior MR vaccination at 6 months of age - Secondary objectives 1. To assess the frequency of adverse reactions following administration of MR vaccine at 6 months 2. To compare the immunogenicity of the MR vaccine first dose administered at 6 months vs at 9 months. 3. To assess the proportion of mothers with undetectable, detectable and protective levels of measles and rubella antibodies 4. To determine the extent of variation in measles antibodies in women of child bearing age in a population with a long standing measles vaccination program 5. To determine the extent of variation in rubella antibodies in women of child bearing age in a population where rubella vaccine have been recently introduced 6. To determine if variation in antibody levels in infants at 6 months is predominately explained by variation in starting antibody levels in the mother in this population 7. To estimate the half-life of decay of measles and rubella antibodies in infants