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VACCINES & IMMUNISATION

Dr. I. M. Gemmill Medical Officer of Health KFL&A Public Health Kingston, Canada Associate Professor Department of Community Health & Epidemiology Department of Family Medicine, Queen’s University. VACCINES & IMMUNISATION. Hosted by Paul Webber paul@webbertraining.com

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VACCINES & IMMUNISATION

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  1. Dr. I. M. Gemmill Medical Officer of Health KFL&A Public Health Kingston, Canada Associate Professor Department of Community Health & Epidemiology Department of Family Medicine, Queen’s University VACCINES & IMMUNISATION Hosted by Paul Webber paul@webbertraining.com www.webbertraining.com A Webber Training Teleclass I. M. GEMMILL, MD, CCFP, FRCP(C)

  2. IMMUNISATION OBJECTIVES • To describe the value of vaccines in reducing the morbidity and mortality from communicable diseases • To describe the various types of vaccines, desirable qualities in a vaccine, their components and how they work • To describe correct storage, handling, administration and documentation of immunisation • To describe the nature of side effects of vaccines and to distinguish between real and alleged side effects • To communicate effectively with vaccine recipients and their parents about the benefits and risks of vaccines • To outline reputable and disreputable sources of information on immunisation I. M. GEMMILL, MD, CCFP, FRCP(C)

  3. IMMUNISATION COST BENEFIT OF VACCINE ‘Vaccination programmes are considered to be the most cost-beneficial health intervention and one of the few that systematically demonstrate far more benefits than costs.’ InterventionCost per Life Year Saved MMR vaccine for children : < 0$ Mammography > 50 : 810$ Smoking cessation advice (> 1 ppd) : 9800$ Low cholesterol diet (men >20, >180 mg/dl) : 360.000$ I. M. GEMMILL, MD, CCFP, FRCP(C)

  4. IMMUNISATION POLIO INCIDENCE 1949-1995 I. M. GEMMILL, MD, CCFP, FRCP(C)

  5. IMMUNISATION DIPHTHERIA CASES 1924-1995 I. M. GEMMILL, MD, CCFP, FRCP(C)

  6. IMMUNISATION TETANUS DEATHS 1924-1995 I. M. GEMMILL, MD, CCFP, FRCP(C)

  7. IMMUNISATION MEASLES INCIDENCE 1924-1995 I. M. GEMMILL, MD, CCFP, FRCP(C)

  8. IMMUNISATION RUBELLA CASES 1924-1995 I. M. GEMMILL, MD, CCFP, FRCP(C)

  9. IMMUNISATION IMPACT OF VACCINES ON COMMUNICABLE DISEASES IN CANADA DISEASEBefore vaccine*2001 Diphtheria 9000 0 Polio 20.000 0 Measles 300.000 33 Rubella 69.000 23 *Number of cases in an outbreak year I. M. GEMMILL, MD, CCFP, FRCP(C)

  10. IMMUNISATION TYPES OF IMMUNISATION Active immunisation: • the formation of antibodies in response to an antigenic stimulus • protection tends to be long-term Passive immunisation: • the administration of preformed antibody, from a human or animal source, to provide short-term protection against disease • e.g. gamma globulin, specific immune globulin I. M. GEMMILL, MD, CCFP, FRCP(C)

  11. IMMUNISATION QUALITIES OF A GOOD VACCINE • Effective • immunogenicity: • induces antibodies in individuals • efficacy • reduces disease in populations • duration of protection: • need for boosters is limited I. M. GEMMILL, MD, CCFP, FRCP(C)

  12. IMMUNISATION QUALITIES OF A GOOD VACCINE • Safe • common side effects are mild • serious side effects are rare • does not cause disease • not transmissible to others I. M. GEMMILL, MD, CCFP, FRCP(C)

  13. IMMUNISATION QUALITIES OF A GOOD VACCINE • Ease of administration • injectable • needle • jet injector • nasal spray • oral • edible I. M. GEMMILL, MD, CCFP, FRCP(C)

  14. IMMUNISATION QUALITIES OF A GOOD VACCINE • Stability • Freezer stable • Fridge stable • Stable at room temperature I. M. GEMMILL, MD, CCFP, FRCP(C)

  15. IMMUNISATION QUALITIES OF A GOOD VACCINE • Cost • Older vaccines cost a few dollars per dose • Newer vaccines enter the market at 60$ per dose or higher • Competition brings the price down I. M. GEMMILL, MD, CCFP, FRCP(C)

  16. IMMUNISATION HOW DO VACCINES WORK? Vaccines cause the immune system to provide protection against disease without causing disease They stimulate an immune response to provide protective antibodies, memory cells, or both I. M. GEMMILL, MD, CCFP, FRCP(C)

  17. IMMUNISATION NEW VACCINE DEVELOPMENT Vaccines go through a number of processes: • Bench research • Animal trials • Clinical trials for safety & efficacy • Licensure • National expert recommendations • Field use: private pay or provincial programme I. M. GEMMILL, MD, CCFP, FRCP(C)

  18. IMMUNISATION VACCINES MANUFACTURING Vaccines are among the most rigorously controlled medical products: • Production & purification of the desired antigen • Inactivation or disruption • Sterilisation • Packaging & preservatives I. M. GEMMILL, MD, CCFP, FRCP(C)

  19. IMMUNISATION TYPES OF VACCINES Live vaccines: • measles, mumps, rubella • varicella • yellow fever • oral polio vaccine (Sabin) • BCG I. M. GEMMILL, MD, CCFP, FRCP(C)

  20. IMMUNISATION TYPES OF VACCINES Killed vaccines, whole cell: • polio • rabies • hepatitis A Killed vaccines, particles: • pertussis • influenza I. M. GEMMILL, MD, CCFP, FRCP(C)

  21. IMMUNISATION TYPES OF VACCINES Killed vaccines, polysaccharide: • meningococcal • pneumococcal Killed vaccines, conjugated: • meningococcal • pneumococcal • haemophilus influenzae I. M. GEMMILL, MD, CCFP, FRCP(C)

  22. IMMUNISATION TYPES OF VACCINES With live vaccines, a small amount of vaccine virus is administered The vaccine virus replicates, thereby mimicking the disease process more closely The protection that they provide is generally therefore longer-lasting and requires fewer total doses The fact that live virus replicates in this process means that these vaccines have special precautions : • Pregnancy • People whose immune status is compromised • Cold chain must be respected I. M. GEMMILL, MD, CCFP, FRCP(C)

  23. IMMUNISATION TYPES OF VACCINES With vaccines that are not live, the total dose administered is all that the immune system has to work with Some vaccines therefore have adjuvants or protein carriers to make them more immunogenic I. M. GEMMILL, MD, CCFP, FRCP(C)

  24. IMMUNISATION COMPONENTS OF VACCINES Vaccines contain: • Antigens to induce an immune response Vaccines may also contain: • Adjuvant: aluminium hydroxide • Preservatives: thimerosal • Antibiotics: neomycin • Other stabilisers: albumin I. M. GEMMILL, MD, CCFP, FRCP(C)

  25. IMMUNISATION VACCINE INDICATIONS • Indications for use are based on epidemiological risk • May be for universal use e.g. pertussis • May be for targeted populations e.g. travel, lifestyle • May be for pre-exposure (routine) use • May be for post-exposure (outbreak control) use e.g. hepatitis A • Refer to national expert statements for indications, rather than product monographs I. M. GEMMILL, MD, CCFP, FRCP(C)

  26. IMMUNISATION VACCINE SCHEDULES Every vaccine has a schedule of administration The schedule is determined by clinical trial design and post-marketing research The product monograph is a legal document providing the most conservative approach to vaccine use Recommendations of expert bodies are the most valid sources for reference for vaccine use I. M. GEMMILL, MD, CCFP, FRCP(C)

  27. IMMUNISATION VACCINE SCHEDULES Some vaccines have more flexible schedules than others : • hepatitis B vaccine vs. conjugated pneumococcal Schedules need to accommodate the requirements and precautions for all vaccines that are recommended e.g. timing of live virus vaccines I. M. GEMMILL, MD, CCFP, FRCP(C)

  28. IMMUNISATION IMMUNE MEMORY AND THE NEED FOR BOOSTERS There are two ways in which vaccines protect: • Antibodies are produced that may last for years • Memory cells may be produced, that create antibodies quickly in response to an antigenic challenge • We judge vaccines by antibody, but they may protect through the second mechanism I. M. GEMMILL, MD, CCFP, FRCP(C)

  29. IMMUNISATION IMMUNE MEMORY AND THE NEED FOR BOOSTERS • Some vaccines need only one dose for lasting protection • Conjugated meningococcal vaccine in adults • Most vaccines need more than one dose to be fully effective • Some vaccines need regular boosting throughout life • Toxoids: tetanus & diphtheria I. M. GEMMILL, MD, CCFP, FRCP(C)

  30. IMMUNISATION IMMUNE MEMORY AND THE NEED FOR BOOSTERS • Live virus vaccines may need less doses in general because they mimic the disease process better • Oral polio requires more than one dose because one of the three types predominates with ease dose • Some vaccines just work incredibly well after two or three doses • hepatitis A, inactivated polio I. M. GEMMILL, MD, CCFP, FRCP(C)

  31. IMMUNISATION VACCINE ADMINISTRATION There are several ways to administer vaccines: • IM • SC (usually live virus vaccines) • Oral • ID The route of administration is specific to each vaccine. It is essential to check and be sure of the route of administration for a given vaccine. I. M. GEMMILL, MD, CCFP, FRCP(C)

  32. IMMUNISATION VACCINE ADMINISTRATION Technique: • Use the right-sized needle (e.g. 1 inch for adult I.M.) • Deltoid for adults and older children • Anterolateral surface of the thigh for infants and young children • No gluteal injections • Sharp needles only I. M. GEMMILL, MD, CCFP, FRCP(C)

  33. IMMUNISATION VACCINE ADMINISTRATION Technique: • Cleanse the area with alcohol and let it evaporate • Separate needle and syringe for each injection • Aspirate • Practise doing it quickly, so that patients are less uncomfortable I. M. GEMMILL, MD, CCFP, FRCP(C)

  34. IMMUNISATION VACCINE TIPS • Prophylactic use of antipyretics may decrease minor side effects • Interruption of the recommended schedule does not usually mean restarting (exception: conjugated pneumococcal) • Giving a vaccine after too short an interval is a problem • Recommended vaccine dosage should NEVER be reduced • Prematurity does not affect vaccines schedules I. M. GEMMILL, MD, CCFP, FRCP(C)

  35. IMMUNISATION STORAGE & COLD CHAIN • The storage requirements may vary from vaccine to vaccine • Storage requirements must be respected • Some vaccines can undergo one insult without loss but no insult to the vaccine is preferred • Live virus vaccines are generally more susceptible to insult that others • The prime example is fridge failure • In general, most vaccines are kept at 2 to 8° C I. M. GEMMILL, MD, CCFP, FRCP(C)

  36. IMMUNISATION IMMUNISATION RECORDS Every immunisation event should be recorded on the patient’s chart and a record provided to the vaccinee Immunisations are reportable in some provinces Provincial systems vary from province to province but are not connected There is currently no national system to keep track of immunisations I. M. GEMMILL, MD, CCFP, FRCP(C)

  37. IMMUNISATION VACCINE SAFETY MONITORING • Vaccines are probably the best monitored of all medical interventions • The process of licensing vaccines is rigorous (average 2 years) • There is a requirement to report possible AVEs in most provinces • Companies conduct post-marketing surveillance • Immunisation Monitoring Programme ACTive (IMPACT) • Advisory Committee on Causality Assessment (ACCA) I. M. GEMMILL, MD, CCFP, FRCP(C)

  38. IMMUNISATION VACCINE CONTRAINDICATIONS The only true contraindication to any vaccine is a previous anaphlylactic reaction or severe hypersensitivity to any component of the vaccine. I. M. GEMMILL, MD, CCFP, FRCP(C)

  39. IMMUNISATION VACCINE CONTRAINDICATIONS Contraindications to live virus vaccines: • Pregnancy: • although no birth defect has ever been recorded • may have to balance risk versus benefit e.g. Yellow Fever vaccine • Some immunodeficiency states I. M. GEMMILL, MD, CCFP, FRCP(C)

  40. IMMUNISATION VACCINE SIDE EFFECTS SIDE EFFECTS INCLUDE: • Local (at the injection site): • Swelling, induration, tenderness, erythema • Systemic (examples): • Fever, rash, arthralgia, myalgia, • Severe: anaphylaxis, GBS I. M. GEMMILL, MD, CCFP, FRCP(C)

  41. IMMUNISATION VACCINE SIDE EFFECTS • Common side effects are generally milder • Serious side effects are generally rare • Side effects may vary from vaccine to vaccine, based on the components • Some side effects are simply owing to the injection I. M. GEMMILL, MD, CCFP, FRCP(C)

  42. IMMUNISATION VACCINE SIDE EFFECTS • Every medical intervention has risks • Vaccines are no exception • Patients must be informed about risks and side effects • Informed consent for immunisation is a requirement I. M. GEMMILL, MD, CCFP, FRCP(C)

  43. IMMUNISATION VACCINE SIDE EFFECTS CONDITIONS THAT ARE NOT DUE TO VACCINES: • Chronic fatigue syndrome (hepatitis B vaccine) • Multiple sclerosis (hepatitis B vaccine) • Autism (MMR vaccine, vaccines containing thimerosal) • Ulcerative colitis (MMR vaccine) • Brain damage (pertussis vaccine) • SIDS (many vaccines) I. M. GEMMILL, MD, CCFP, FRCP(C)

  44. IMMUNISATION VACCINE PRECAUTIONS • There are precautions for giving any medical intervention, including vaccines • Precautions are specific to the vaccine • Example: • Live virus vaccines must be given at the same time or with an interval of at least 28 days I. M. GEMMILL, MD, CCFP, FRCP(C)

  45. IMMUNISATION VACCINES IN PREGNANCY • Live virus vaccines are contraindicated in pregnancy because of the theoretical risk of congenital anomaly • Inadvertent immunisation of a pregnant woman with a live virus vaccine should be reported for monitoring purposes • Other vaccines may be used safely in pregnancy • Risk versus benefit must be considered • Some vaccines are indicated in pregnancy : • influenza I. M. GEMMILL, MD, CCFP, FRCP(C)

  46. IMMUNISATION VACCINE RISK VERSUS BENEFIT • Every vaccine as some small risk attached to it • The benefit of vaccine normally far outweighs any risk • Sometimes, it is better to respect even a theoretical risk e.g. live virus vaccine in pregnancy • Example: YF vaccine in immunocompromised travellers • If the risk outweighs the benefit, vaccine should not be administered e.g. smallpox vaccine I. M. GEMMILL, MD, CCFP, FRCP(C)

  47. IMMUNISATION COMMUNICATING RISK VERSUS BENEFIT The advice of a health professional is the most important factor in whether a person receives a vaccine Clear, simple, concise information must be provided about both the risks and the benefits of vaccines (CMPA policy on pneumococcal & meningococcal vaccines) Some people may need more detailed explanations than others Public health and professional bodies can help I. M. GEMMILL, MD, CCFP, FRCP(C)

  48. IMMUNISATION MYTHS ABOUT VACCINES Common myths about vaccines: • Vaccines don’t really work • Vaccines aren’t safe • We don’t need vaccines because the diseases are rare • There are too many antigens given to children now • Vaccines weaken the immune system • A healthy lifestyle is all one needs to prevent infection • There is an industry conspiracy to poison children for profit I. M. GEMMILL, MD, CCFP, FRCP(C)

  49. IMMUNISATION ANTI-VACCINATIONISTS There is a small group of zealots who are opposed to vaccine They believe that vaccines are unsafe and subscribe to conspiracy theories about them They are willing to spread untruths about vaccines publicly They may cause damage to public programmes : • hepatitis B in Manitoba, France I. M. GEMMILL, MD, CCFP, FRCP(C)

  50. IMMUNISATION ANTI-VACCINATIONISTS There are many books published and web sites maintained by the anti-vaccine faction Many have respectable names and purport to be authoritative Some are supported by health paraprofessionals I. M. GEMMILL, MD, CCFP, FRCP(C)

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