The purpose of this study is to evaluate the safety of a new conjugate vaccine, NmVac4-A/C/Y/W-135-DT, compared to the safety of a similar, licensed meningococcal A/C/Y/W-135-DT conjugate vaccine. The investigators will also evaluate the production of antibodies to of NmVac4-A/C/Y/W-135-DT™ conjugate vaccine compared to the licensed vaccine, as a measure of vaccine effectiveness.

Meningococcal disease is a potentially life-threatening bacterial infection. The disease most commonly is expressed as either meningococcal meningitis, an inflammation of the membranes surrounding the brain and spinal cord, or meningococcemia, the presence of bacteria in the blood. The most common symptoms include high fever, headache, neck stiffness, confusion, nausea, vomiting, lethargy, and rash. If not treated the disease can progress rapidly and can lead to shock and death, often within hours of the onset of symptoms. Neisseria meningitidis capsular polysaccharides are poor immunogens. However, conjugation of bacterial polysaccharides to immunogenic carrier proteins generally results in conjugates that induce strong anti-polysaccharide T-helper cell dependent immune responses, creating a longer-lasting immune response and thus protection against meningococcal infection. This study compares safety and antibody production induced by one intramuscular injection of either NmVac4-A/C/Y/W-135-DT or a licensed meningococcal A/C/Y/W-135-DT conjugate vaccine. Participants will attend a screening visit up to 4 weeks prior to Day 0, then will attend study visits for 8 weeks. There will be a study phone call at Days 2-3, then a post-study telephone call to subjects to assess safety at 26 weeks.

Inclusion Criteria:

• Willing and able to give informed consent and comply with all aspects of the evaluation after the nature of the study is explain
• For the purpose of this study, a healthy volunteer is defined as healthy male or female, with no significant chronic conditions
• Age 18 to 50 years old
• Either gender. Abstinence or use of contraception during the eight weeks after vaccination will be required for non menopausal (< two years post-menopause) or non surgically sterile women
• Persons with antibody titer(s) of <2 µg/mL to serogroup(s) A, C, Y, or W-135 polysaccharides as measured by ELISA

Exclusion Criteria:

• Age less than 18 years or over 50 years.
• History of Guillain-Barré syndrome (GBS).
• Pregnancy or lactation.
• History of meningococcal meningitis.
• History of invasive (clinical or laboratory diagnosis) meningococcal disease.
• History of meningococcal meningitis vaccination.
• Screening laboratory abnormalities (in the opinion of the Investigator) that would raise safety concerns for participation in the study.
• Use of immunosuppressive drugs within 30 days prior to study enrollment, not including topical or inhaled steroids/cytotoxic agents.
• History of anaphylactic shock, asthma, urticaria, or other allergic or hypersensitivity reactions following vaccination.
• History of severe allergic disorders or autoimmune connective tissue disorders, including rheumatoid arthritis. A high sensitivity C-Reactive Protein (CRP) test at screening will be used as part of the assessment of autoimmune disorders by the Principal Investigator.
• Use of systemic antibiotics within 72 hours prior to study enrollment.
• History of cirrhosis.
• Positive results of testing for HepBsAg, Hepatitis C or HIV-1 or HIV-2 antibodies.
• Positive results of drug screen (amphetamine, THC, cocaine).
• Persons with antibody titer(s) of >2 µg/mL to serogroup (s) A, C, Y, or W 135 as measured by ELISA.
• Unable to understand all of the study requirements.
• Prisoners.
• Participation in a clinical trial in the last three months.
• History of any serious chronic medical or psychiatric illnesses.
• History of significant head trauma, alcohol or substance abuse or other medical illnesses that could cause a neurological deficit (e.g., cerebro-vascular disease) .
• Chronic medication use that, in the opinion of the Investigator, may influence or bias the clinical outcome of the trial.
• Individuals will be excluded from participation in this trial if they are judged by the Principal Investigator as having a significant impairment in their capacity for judgment or reasoning that compromise their ability to make decisions in their best interest.