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

Inclusion Criteria:

1. Age between 2-29 years, both sexes, living in the selected villages of Butajira area
2. A written informed consent signed by the individual (>=18y) or caretaker/guardian (2 to 17 years of age) as 18 is the legal age of maturity in Ethiopia. Assent from children/adolescents aged 12-17 years old.
3. Free of obvious health problems ascertained by medical history and clinical examination on the day of enrolment

Exclusion Criteria:

1. Those who are unlikely to complete the follow up at 4-weeks post-vaccination.
2. Use of any investigational or non-registered drug or vaccine other than the study vaccines within 30 days preceding the first dose of study vaccine, or planned use during the study period.
3. Administration of blood transfusion within 2 years prior to enrolment or planned use during the study period.
4. Verbal report of previous vaccination with meningococcal serogroup A, C, Y or W135 vaccines since 1999.
5. Confirmed or suspected immunosuppressive or immunodeficient condition including HIV infection.
6. A family history of congenital or hereditary immunodeficiency.
7. History of allergic reaction to any component of the vaccine
8. Presence of any fever (defined as axillary temperature of 37.5 degree centigrade or more) and/or severe illness on the day of enrolment/ vaccination.
9. Pregnancy.
10. lactation