1. Principles of Vaccination Epidemiology and Prevention of Vaccine- Preventable Diseases Source: Centers for Disease Control and Prevention

2. Principles of Vaccination Self vs. nonself Protection from infectious disease Usually indicated by the presence of antibody Very specific to a single organism Immunity

3. Principles of Vaccination Protection produced by the person's own immune system Usually permanent Protection transferred from another person or animal Temporary protection that wanes with time Active Immunity Passive Immunity

4. Principles of Vaccination A live or inactivated substance (e.g., protein, polysaccharide) capable of producing an immune response Protein molecules (immuno- globulin) produced by B lymphocytes to help eliminate an antigen Antigen Antibody

5. Passive Immunity Transfer of antibody produced by one human or other animal to another Temporary protection Transplacental most important source in infancy

6. Sources of Passive Immunity Almost all blood or blood products Homologous pooled human antibody (immune globulin) Homologous human hyperimmune globulin Heterologous hyperimmune serum (antitoxin)

7. Monoclonal Antibody Derived from a single type, or clone, of antibody-producing cells (B cells) Antibody is specific to a single antigen or closely related group of antigens Used for diagnosis and therapy of certain cancers and autoimmune and infectious diseases

8. Antibody for Prevention of RSV Palivizumab (Synagis) – monoclonal – contains only RSV antibody – will not interfere with the response to a live virus vaccine

9. Vaccination Active immunity produced by vaccine Immunity and immunologic memory similar to natural infection but without risk of disease

10. Classification of Vaccines Live attenuated – viral – bacterial Inactivated

11. Inactivated Vaccines viruses bacteria protein-based – toxoid – subunit polysaccharide-based – pure – conjugate Whole Fractional

12. Principles of Vaccination General Rule The more similar a vaccine is to the disease-causing form of the organism, the better the immune response to the vaccine

13. Live Attenuated Vaccines Attenuated (weakened) form of the "wild" virus or bacterium Must replicate to be effective Immune response similar to natural infection Usually produce immunity with one dose* *except those administered orally

14. Live Attenuated Vaccines Severe reactions possible Interference from circulating antibody Fragile – must be stored and handled carefully

15. Live Attenuated Vaccines Viral measles, mumps, rubella, varicella/zoster, yellow fever, rotavirus, intranasal influenza, rotavirus, vaccinia Bacterial BCG, oral typhoid

16. Inactivated Vaccines Cannot replicate Generally not as effective as live vaccines Less interference from circulating antibody than live vaccines Generally require 3-5 doses Immune response mostly humoral Antibody titer may diminish with time

17. Inactivated Vaccines Viral polio, hepatitis A, rabies, influenza* Bacterial pertussis*, typhoid* cholera*, plague* Whole-cell vaccines *not available in the United States

18. Inactivated Vaccines Subunit hepatitis B, influenza, acellular pertussis, human papillomavirus, anthrax Toxoid diphtheria, tetanus Fractional vaccines

19. Pure Polysaccharide Vaccines Not consistently immunogenic in children younger than 2 years of age No booster response Antibody with less functional activity Immunogenicity improved by conjugation

20. Polysaccharide Vaccines pneumococcal meningococcal Salmonella Typhi (Vi) Haemophilus influenzae type b pneumococcal meningococcal Pure polysaccharide Conjugate polysaccharide

21. Vaccine Safety Epidemiology and Prevention of Vaccine- Preventable Diseases Centers for Disease Control and Prevention

22. Importance of Vaccine Safety Vaccines Decrease risk of disease onset; associated risks must be carefully considered to maintain public confidence. – higher standard of safety is expected of vaccines – vaccinees generally healthy (vs. ill for drugs) – lower risk tolerance = need to search for rare reactions – vaccination universally recommended and mandated

23. Diphtheria 175,885 0 100 Measles 503,282 55 99.9 Mumps 152,209 6,584 95.7 Pertussis 147,271 15,632 89.4 Polio (paralytic) 16,316 0 100 Rubella 47,745 11 99.9 Congenital Rubella Syn. 823 1 99.9 Tetanus 1,314 41 96.9 H. influenzae type b 20,000+ 208 99.0 and unknown (<5 yrs) Disease Pre-vaccine Era* 2006** % decrease * Baseline 20 th century annual morbidity + Estimated because no national reporting existed in the pre-vaccine era ** Source: MMWR 2007;56(33):851-64 Comparison of Pre-Vaccine and Current Reported Morbidity of Vaccine-Preventable Diseases and Vaccine Adverse Events, United States Total 1,064,854 22,532 97.9 Vaccine Adverse Events N/A 15,484 +++

24. Importance of Vaccine Safety Ongoing safety monitoring needed for the development of sound policies and recommendations

25. Prelicensure Vaccine Safety Studies Laboratory Animals Humans

26. Prelicensure Human Studies Phases I, II, III trials Common reactions are identified Vaccines are tested in thousands of persons before being licensed and allowed on the market

27. Postlicensure Surveillance Identify rare reactions Monitor increases in known reactions Identify risk factors for reactions Identify vaccine lots with unusual rates or types of events Identify signals

28. Postlicensure Vaccine Safety Activities Phase IV Trials – ~10,000 participants – better but still limited Large-Linked Databases Clinical Immunization Safety Assessment Network

29. Vaccine Adverse Event Reporting System (VAERS) National reporting system Jointly administered by CDC and FDA Passive (depends on healthcare providers and others to report) Receives ~15,000 reports per year

30. Vaccine Adverse Event Reporting System (VAERS) Detects – new or rare events – increases in rates of known side effects – patient risk factors Additional studies required to confirm VAERS signals Not all reports of adverse events are causally related to vaccine

31. Adverse Event Classification Vaccine-induced Vaccine-potentiated Programmatic error Coincidental

32. Vaccine Safety Datalink (VSD) Large-linked database Links vaccination and health records “Active surveillance” – 8 Managed Care Organizations – ~3% of the U.S. population Powerful tool for monitoring vaccine safety

33. Clinical Immunization Safety Assessment (CISA) Network Improve understanding of vaccine safety issues at individual level Evaluate persons who experience adverse health events Gain better understanding of events Develop protocols for healthcare providers

34. Vaccine Injury Compensation Program (VICP) Established by National Childhood Vaccine Injury Act (1986) “No fault” program Covers all routinely recommended childhood vaccines Vaccine Injury Table

35. The Provider’s Role Immunization providers can help to ensure the safety and efficacy of vaccines through proper: – vaccine storage and administration – timing and spacing of vaccine doses – observation of contraindications and precautions

36. The Provider’s Role Immunization providers can help to ensure the safety and efficacy of vaccines through proper: – management of vaccine side effects – reporting of suspected side effects to VAERS – vaccine benefit and risk communication

37. Contraindication A condition in a recipient that increases the chance of a serious adverse reaction

38. Precaution A condition in a recipient that might Increase the chance or severity of an adverse reaction, or Compromise the ability of the vaccine to produce immunity

39. Invalid Contraindications to Vaccination Minor illness Mild/moderate local reaction or fever following a prior dose Antimicrobial therapy Disease exposure or convalescence Pregnancy or immunosuppression in the household Premature birth Breastfeeding Allergies to products not in vaccine Family history (unrelated to immunosuppression)

40. Benefit and Risk Communication Opportunities for questions should be provided before each vaccination Vaccine Information Statements (VISs) – must be provided before each dose of vaccine – public and private providers – available in multiple languages

41. CDC Vaccines and Immunization Contact Information Telephone 800.CDC.INFO Email nipinfo@cdc.gov Website www.cdc.gov/vaccines