The purpose of the study is to compare the immunological response of homeopathic vaccines to placebo and to conventional vaccines in healthy young adults.

Inclusion Criteria:

• Between the ages of 18 and 24 years
• Has received primary childhood DTaP and MMR vaccinations
• Available for a follow up visit (3 weeks after initial visit)

Exclusion Criteria:

• Received a live vaccine in the past 4 weeks
• Has had a serious allergic reaction to a previous vaccination
• Has allergies to one or more of the components of the vaccines to be used (Neomycin, egg protein)
• Has a history of encephalopathy within 7 days of receiving DTP/DTap
• Has received nosodes for Diphtheria, Tetanus, Pertussis, Measles and Mumps
• Has received an adult booster dose of conventional vaccines of diphtheria, pertussis, tetanus, mumps, and measles (Tdap or MMR)
• Has received immunosuppressive doses of steroids or anti-cancer drugs in the past 3 months
• Is pregnant or if there is a chance they could become pregnant during the next month
• Has a moderate to severe acute illness at the time of enrolment
• Has cancer, leukemia, HIV/AIDS, or any other serious immune health condition
• Has a history of Guillaume Barre Syndrome
• Has received blood transfusion, blood products, or immune globulin within the past year