Note to presenter: The National Immunization Program can provide a videotape with animated sequences illustrating the biology of active and passive immunity and vaccination with live and inactivated vaccines. Contact us by at if you with to obtain a copy of this tape.
Principles of Vaccination Epidemiology and Prevention of Vaccine- Preventable Diseases National Immunization Program Centers for Disease Control and Prevention Revised March 2002
Principles of Vaccination Self vs. non-self Protection from infectious disease Usually indicated by the presence of antibody Very specific to a single antigen Immunity
Principles of Vaccination Protection produced by the person's own immune system Usually permanent Protection transferred from another person or animal as antibody Active Immunity Passive Immunity A2
Principles of Vaccination A live or inactivated substance (e.g., protein, polysaccharide) capable of producing an immune response Protein molecules (immunoglobulin) produced by B lymphocytes to help eliminate an antigen Antigen Antibody
Passive Immunity Transfer of antibody from an exogenous source Transplacental most important source in infancy Temporary protection
Sources of Passive Immunity Almost all blood or blood products Homologous pooled human antibody (immune globulin) Homologous human hyperimmune globulin Heterologous hyperimmune serum (antitoxin)
RSV-IGIV –Human hyperimmune globulin –Contains other antibodies Palivizumab (Synagis) –Monoclonal –Contains only RSV antibody Antibody for Prevention of RSV
Vaccination Active immunity produced by vaccine Immunity and immunologic memory similar to natural infection but without risk of disease
Classification of Vaccines Live attenuated –viral –bacterial Inactivated
Inactivated Vaccines virus bacteria protein-based –subunit –toxoid polysaccharide-based –pure –conjugate Whole Fractional
Principles of Vaccination General Rule The more similar a vaccine is to the natural disease, the better the immune response to the vaccine.
Live Attenuated Vaccines Attenuated (weakened) form of the "wild" virus or bacteria Must replicate to be effective Immune response similar to natural infection Usually effective with one dose
Live Attenuated Vaccines Severe reactions possible Interference from circulating antibody Unstable
Live Attenuated Vaccines Viralmeasles, mumps, rubella, vaccinia, varicella, yellow fever (oral polio) (rotavirus) (influenza) BacterialBCG, oral typhoid Vaccines in (parenthesis) are not available in the United States.
Cannot replicate Minimal interference from circulating antibody Generally not as effective as live vaccines Generally require 3-5 doses Immune response mostly humoral Antibody titer falls over time Inactivated Vaccines
Viralpolio, hepatitis A, rabies (influenza) Bacterial(pertussis) (typhoid) (cholera) (plague) Whole cell vaccines Vaccines in (parenthesis) are not available in the United States.
Inactivated Vaccines Subunithepatitis B, influenza, acellular pertussis, typhoid Vi (Lyme) Toxoiddiphtheria, tetanus Fractional vaccines
Polysaccharide Vaccines pneumococcal meningococcal Haemophilus influenzae type b pneumococcal Pure polysaccharide Conjugate polysaccharide
Pure Polysaccharide Vaccines Not consistently immunogenic in children <2 years of age No booster response Antibody with less functional activity Immunogenicity improved by conjugation
National Immunization Program Hotline Websitewww.cdc.gov/nip