antibody responses following meningococcal tetravalent (a, c, y, and w-135) conjugate vaccination in healthy adults

Conditions: Meningitis; Meningococcemia

Summary: this study was designed to generate data for the assessment of meningococcal polysaccharide diphtheria toxoid conjugate vaccine (menactra®) when given to adults aged 18 to 55 years. primary objective: to describe the antibody response to each serogroup prior to, and 4 to 6 weeks following, the administration of one dose of the investigational meningococcal polysaccharide diphtheria toxoid conjugate vaccine (menactra®), as measured by serum bactericidal activity using baby rabbit complement (sba br) in participants in each of the two study groups. secondary objective: to collect reference sera for the development and refinement of laboratory assays for the measurement of antibody responses to serogroups y and w 135.

enrollment was terminated before the planned sample size was achieved because the principal investigator and the sponsor decided that sufficient sera had been obtained to meet the secondary objective of the study. there were no safety concerns involved in the decision to stop enrollment. subjects that were enrolled at the time completed the study as per protocol, the last subject last visit was on 29 april 2004.

Eligibility criteria:
inclusion criteria : * participant was at least 18 years of age but not yet 56 years of age at the time of vaccination. * participant had received either unconjugated meningococcal polysaccharide (serogroups a and c, or a, c, y, and w 135) vaccine at least one year prior to enrollment (for assignment to group 2) or had no prior history of meningococcal vaccination (for assignment to group 1). * participant had signed ethics committee-approved informed consent form. exclusion criteria : * serious chronic disease (i.e., cardiac, renal, neurologic, metabolic, rheumatologic, psychiatric, etc.) * known or suspected impairment of immunologic function * acute medical illness with or without fever within the last 72 hours or an oral temperature ≥ 38°c at the time of inclusion * history of documented invasive meningococcal disease * administration of immune globulin or other blood products within the last three months, or injected or oral corticosteroids or other immunomodulatory therapy within six weeks of the study vaccine. individuals on a tapering dose schedule of oral steroids lasting \< 7 days were allowed to be included in the trial as long as they had not received more than one course within the last two weeks prior to enrollment. * antibiotic therapy within the 72 hours prior to vaccination or 72 hours prior to drawing the blood sample at visit 2 * received unconjugated meningococcal polysaccharide (serogroups a and c, or a, c, y, and w 135) vaccine within the one-year period prior to enrollment or a conjugated meningococcal vaccine at any time prior to enrollment * received any vaccine in the 28-day period prior to enrollment, or scheduled to receive any vaccination during participation in the study * suspected or known hypersensitivity to any of the vaccine components * unavailable for the entire study period, or unable to attend the scheduled visits or to comply with the study procedures * enrolled in another clinical trial * in females, pregnancy confirmed by positive urine test result * in females, current breastfeeding.

Keywords: menactra® meningitis meningococcemia neisseria meningitidis