Primary objective:
To assess the immunogenicity of the Mencevax ACW135 polysaccharide vaccine at 28 days (+6days) post vaccination in 2-4, 5-14, 15-29 year age groups and compare the immunogenicity between these age groups.
Secondary Objectives:
- To estimate the incidence of common adverse events following immunization (AEFI) of GSK Nm ACW135 polysaccharide vaccine at 1h, 1d, 2d, 3d, 7d and 28 days post-vaccination
- To assess the persistence of antibody against meningitis A, C and W135 at 11 and 23 months post vaccination in 2-4, 5-14, 15-29 year age groups
Study site:Two rural communities (Kebele) in Butajira district, Ethiopia.
Methods:
- Phase II, open and parallel safety and immunogenicity trial.
- 234 younger children (2-4 years), 145 older children (5-14 years) and 33 adults (15-29 years of age) were randomly selected from the demographic surveillance database and enrolled after screening and consenting.
- Study participant received Mencevax ACW polysaccharide vaccine 50 mg in 0.5ml subcutaneously.
- Blood samples for measuring SBA titres were collected at pre vaccination and on day 28 (+6 days) post vaccination.
- Active follow up for AEFI on post vaccination day 0, 1, 2, 3, 7, & 28.
- Primary end point was vaccine response defined as sero-conversion (in subjects initially seronegative) or a 4 fold increase (in subjects initially seropositive) in serum bactericidal antibodies (SBA) against serogroups Men A, C and W135) on post vaccination day 28. In addition seroconversion was assessed by ELISA Men A IgG on day 0 and day 28 post vaccination.
- Secondary endpoints were incidence of general and local symptoms and other adverse events following immunisation during the post vaccination period day 0 to 28 and immune persistence on post vaccination month-11 and month-23.
Results:
- No significant difference in the incidence of general or local AEFI was observed between the age groups
- The statistical analysis for the Immunogenicity data is in progress