Immunization Update. 23 rd October Natasha S. Crowcroft Chief, Infectious Diseases Public Health Ontario

Transcription

1 Immunization Update 23 rd October 2013 Natasha S. Crowcroft Chief, Infectious Diseases Public Health Ontario

2 Immunization: It s Your Best Shot! Faculty/Presenter Disclosure Faculty: Dr. Natasha Crowcroft Relationships with commercial interests: Grants/Research Support: not applicable Speakers Bureau/Honoraria: not applicable Consulting Fees: not applicable Other: not applicable 2

3 Immunization: It s Your Best Shot! Disclosure of Commercial Support This program has received financial support from the Ministry ofhealth and Long-Term Care This program has not received in-kind support. Potential for conflict(s) of interest: None Mitigating Potential Bias: Not applicable 3

4 Outline Information Resources Live versus inactivated vaccines Intervals between vaccines Catch up schedules Asplenia and hyposplenia Solid organ transplantation Pneumococcal vaccine Measles, mumps, rubella Varicella HPV Other questions 4

5 Questions for you to ponder! 1. With each additional dose of vaccine, does the risk of adverse events following MMR a. Increase? b. Decrease? 2. Which pneumococcal vaccine is publicly funded for those aged 65 years and above? 3. Is pneumococcal immunization recommended for patients with diabetes mellitus? 5

6 Sources of information: NACI 6

7 New statements from NACI 2013: Update on the Use of Quadrivalent Conjugate Meningococcal Vaccines 7

8 Canadian Immunization Guide 8

9 Canadian Paediatric Society resources 9

10 Immunization Canada 10

11 Local knowledge: PHO, MOHLTC, Peel 11

12 Live vaccines For example: MMRV Attenuated strains which replicate in host Attenuation-the virus or bacterium has been weakened to reduce virulence so it cannot cause disease in healthy people Acts like natural infection Live vaccines are the closest to actual infection and therefore elicit good, strong, long-lasting immune responses 12

13 Live vaccines Advantages Single dose often sufficient to induce long-lasting immunity Strong immune response evoked Local and systemic immunity produced Disadvantages Potential to revert to virulence Contraindicated in immunosuppressed patients Interference by viruses or vaccines and passive antibody Poor stability Potential for contamination 13

14 Inactivated vaccines Suspensions of whole intact killed organisms OR e.g. whole cell pertussis, influenza, rabies, Hepatitis A Acellular and sub-unit vaccines Contain one or a few components of organism important in protection e.g. acellular pertussis vaccine contains between 2-5 components of the whole cell pertussis bacteria e.g. diphtheria toxoid e.g. Hib 14

15 Inactivated vaccines Advantages Stable Constituents clearly defined Unable to cause the infection Disadvantages Need several doses Local reactions common Adjuvant needed keeps vaccine at injection site activates antigen presenting cells Shorter lasting immunity 15

16 Adverse events Live vaccines: frequency of adverse events falls with number of doses Eg MMR, rubella Inactivated vaccines: frequency of adverse events increases with number of doses Eg tetanus, pertussis 16

17 Intervals between each dose of vaccine To allow each immune response to develop e.g. primary immunisation (1 month) To avoid immune interference - live vaccines only Immunoglobulin e.g. rubella susceptible women who are given RhIg in the peripartum period; MMR should be given as soon as possible following delivery, with serologic testing done 2 months later to assess immune response Between live virus vaccines give same day or 4 weeks apart (minimum 3 weeks) To reduce reactions to another component (usually tetanus) It is better to delay a vaccine than to give a dose early. If doses are too close together then boosting may not occur. 17

18 CATCH-UP SCHEDULES 18

19 Publicly funded immunization schedule for Ontario There is no perfect schedule The number of vaccines has increased in recent years, increasing the complexity Rationale for the schedule is partly epidemiology Some simple rules help with catch up schedules blic/programs/immunization/docs/sc hedule.pdf 19

20 Basic principles Schedules do not need to be re-started in incompletely immunized individuals A dose that is given too close to the last dose should not be counted Interval is not defined by Canadian Immunization Guide (CIG). US (ACIP) uses a criterion of divergence of 5 days or more than the recommended interval. Many vaccines are interchangeable (e.g. hepatitis B) Complete the series that was started (ideally) 20

21 Children 1-6 years old 21

22 Children/adolescents 7-17 years old 22

23 Adults 18 years and older 23

24 Splenectomy and solid organ transplantation Which vaccines for Splenectomized and Kidney transplant patients & how often? Canadian Immunization Guide Splenectomy: Immunocompromized: 24

25 Asplenia or Hyposplenia All people, regardless of age, who have absent or defective splenic function are at increased risk of fulminant bacteremia which is associated with a high mortality rate. Risk is highest in the first two years following splenectomy but remains elevated for life. Careful attention should be paid to immunization status when "elective" surgical splenectomy is planned so that all of the necessary vaccines are administered at least 2 weeks before surgery. In the case of an emergency splenectomy, vaccines are best given 2 weeks after the splenectomy for optimal vaccine responses. 25

26 Which vaccines for asplenic or hyposplenic individuals? There are no contraindications to the use of any vaccine for people known to be asplenic or hyposplenic. Particular attention should be paid to ensuring that asplenic or hyposplenic individuals of all ages receive Haemophilus influenzae type b (Hib), meningococcal and pneumococcal vaccines according to recommended schedules, as these individuals are highly susceptible to encapsulated bacteria. Influenza vaccine is recommended annually. Hepatitis A and Hepatitis B vaccines are indicated for those who require repeat transfusions (e.g., sickle cell anemia). 26

27 Solid organ transplantation Solid organ recipients generally receive lifelong immunosuppression, which varies substantially depending on the organ transplanted. Live vaccines are contraindicated. In general, vaccination should not be re-initiated until 3 to 6 months post-transplant when baseline immunosuppression levels are attained. If serologic testing is available and thereis a clear antibody correlate of protection, measurement of post-immunization antibody titres should be considered. Solid organ transplant recipients are at risk of severe illness or death due to influenza, invasive pneumococcal disease, Haemophilus influenzatype b disease and complications of varicella infection 27

28 28

29 Pneumococcal vaccines

30 Pneumococcal vaccine questions Please clarify use of Prevnar-13 vs Pneumovax in adults Pneumovax and diabetes? Prevnar TM 13 (PCV-13) has been licensed for adults >50 but is not publicly funded. Pneumovax 23 (PPV-23) is currently publicly funded for specific high-risk populations and those 65 years and older. In Ontario, PPV-23 is also funded for residents of nursing homes, homes for the aged and chronic care facilities. See the CIG for guidance on the spacing for administration of both PCV-13 and PPV-23 ( 30

31 Pneumococcal conjugate NACI recommendations in children Prevnar 13 if not vaccinated with pneumococcal conjugate and less than 59 months; Prevnar 13 schedule if previously immunized with Prevnar 7 or Synflorix but not Prevnar 13: All children to age 35 months Aboriginal or in child care to age 59 months Consider in others 36 to 59 months Prevnar 13 for all high risk to less than 18 years, including those who completed Prevnar 7 or Synflorix 31

32 High Risk Pneumococcal vaccine recommendations PPV-23 Polysaccharide given beginning at age 2 years If giving both, give conjugate first and polysaccharide 8 weeks later Immunocompromised 50 and older Under consideration to give conjugate followed by polysaccharide 8 weeks later (not funded in Ontario) 32

33 Pneumococcal High Risk Groups Chronic cerebral spinal fluid (CSF) leak Chronic neurologic condition that may impair clearance of oral secretions Cochlear implants (including those children who are to receive implants) Chronic cardiac or pulmonary disease Diabetes mellitus Asplenia (functional or anatomic) Sickle cell disease or other hemoglobinopathies Congenital immunodeficiencies involving any part of the immune system, including B-lymphocyte (humoral) immunity, T-lymphocyte (cell) mediated immunity, complement system (properdin, or factor D deficiencies), or phagocytic functions Hematopoietic stem cell transplant (recipient) HIV infection Immunosuppressive therapy including use of long term corticosteroids, chemotherapy, radiation therapy, post-organ transplant therapy, and certain anti-rheumatic drugs Chronic kidney disease, including nephrotic syndrome Chronic liver disease (including hepatic cirrhosis due to any cause) Malignant neoplasms including leukemia and lymphoma Solid organ or islet transplant (candidate or recipient) 33

34 Pneumococcal conjugate vaccine in adults Some experts suggest giving a conjugate pneumococcal vaccine as the initial dose followed by the PPV-23 vaccine for high risk adults aged less than 65 years, as this may theoretically improve antibody response and immunologic memory. If this strategy is chosen, PPV-13 vaccine should be administered first, followed at least 8 weeks later by PPV-23 vaccine. However, PPV-23 vaccine is the vaccine of choice for these individuals, and if only one vaccine can be provided, it should be PPV-23 vaccine. 34

35 Measles, Mumps and Rubella

36 Measles, Mumps, Rubella (MMR) Routine -immune if any of the following: 12 months to 17 year olds 2 doses Adult without exceptions (exceptions in following slides) born in 1970 or later 1 dose Laboratory confirmed infection or immunity Born before

37 Measles, Mumps, Rubella (MMR) Health care workers and the military, consider immune if any of the following: 2 doses regardless of birth year Laboratory confirmed infection or immunity 37

38 Measles, Mumps, Rubella (MMR) Travellers, immune if any of the following: Born in 1970 or later: 2 doses Born before 1970: 1 dose Laboratory confirmed infection or immunity 38

39 Measles, Mumps, Rubella (MMR) Students in post secondary, consider immune if any of the following: Born in 1970 or later: 2 doses Born before 1970: consider 1 dose Laboratory confirmed infection or immunity 39

40 Varicella

41 Varicella Immunity Consider immune if any of the following: Born before 2004 and have self-reported chicken pox (except health care provider) Born in or after 2004 or health care provider, require: Health care provider diagnosed varicella or zoster Two doses of documented varicella vaccine Laboratory confirmed infection or immunity 41

42 Children with a history of varicella CIG: Children with a history of varicella disease occurring before 12 months of age should receive routine immunization with two doses of varicella-containing vaccine after 12 months of age, because varicella disease at less than 12 months of age has been associated with an increased risk of a second episode of varicella. Children who receive one dose of varicella-containing vaccine and subsequently develop laboratory confirmed breakthrough infection do not require a second dose of a varicellacontaining vaccine for varicella protection. 42

43 Varicella Vaccine Intervals Between two varicella or MMRV vaccines: 12 months to 12 years of age, 3 months Could be 6 weeks if rapid protection needed Between two varicella vaccines 13 year of age and over, 6 weeks Between MMR and V Only 4 weeks is necessary as a minimum interval 43

44 Varicella Vaccine in Adults Adolescents and adults (13 to < 50 years): serology if negative 2 doses For those 50 years of age and over: assume immune only vaccinate with varicella vaccine if known to be susceptible consider zoster vaccine; recommended for 60 years and over 44

45 Influenza vaccine dosing Children 6 months to less than 9 years of age who have never received the seasonal influenza vaccine require two doses of influenza vaccine, with a minimum interval of four weeks between doses. Eligible children <9 years of age who have properly received one or more doses of seasonal influenza vaccine in the past should receive one dose per influenza vaccination season NACI recommends that children 6 to 35 months of age should be given a full dose (0.5 ml) of TIV instead of the previously recommended half dose (0.25 ml). This recommendation applies whether the child is being given one dose of TIV or a two dose series. 45

46 Rationale The full dose is consistent with other vaccines (e.g. diphtheria, pertussis) where we use higher doses for younger children because they respond better. The higher dose is used in other jurisdictions routinely, so in addition to anticipating better protection, we don't anticipate any safety concerns. 46

47 Questions: HPV Will HPV vaccine for boys in grade 8 get public funding in future? The MOHLTC makes policy decision Is HPV vaccine recommended to boys same age group as female counterpart. Recommendation to vaccinate prior to onset of sexual activity, similar to females (ie between 9 and 13 years). Cervarix not approved for males. Gardasil approved for use in males until 26 years, versus 45 years in females Effectiveness of Gardasil? In general > 95% effective 47

48 Other Questions Should we give MMRV vaccine at 4-6 yr check up even if the patient has had 2 MMR vaccinations? No, the child should just receive varicella vaccine Length of effectiveness for zostavax We are not sure as the studies are ongoing, but we currently recommend only one dose Is there a need for mercury content (thimerosal) in our childhood vaccinations? We need preservatives for multi-dose vials to stop potential contamination. Thimerosal is a safe and effective preservative Confusion over catch up schedule? Yes it is confusing! 48

49 Key messages More than you need to know is found in the Canadian Immunization Guide and NACI statements! Between CIG and NACI, the answers to nearly all your questions can be found Some basic principles can help answer many questions 49

50 Questions 1. With each additional dose of vaccine, does the risk of adverse events following MMR a. Increase? b. Decrease? 2. Which pneumococcal vaccine is publicly funded for those aged 65 years and above? 3. Is pneumococcal immunization recommended for patients with diabetes mellitus? 50

51 Acknowledgements Dr. Sarah Wilson, PHO Jill Fediurek, PHO Dr. Shelley Deeks, PHO Dr. Bryna Warshawsky, MLHU, Chair NACI 51