Immunizations and Immune Deficiency

1. Immunizations and Immune Deficiency David B Nelson, MD MSc Professor and Chair Department of Pediatrics Georgetown University

2. Primary Inherited Usually single gene Various types B-lymphocytic T-lymphocytic Complement Phagocytic Secondary (acquired) HIV/Aids Spenectomy Malignant neoplasms Transplant Autoimmune disease Immune suppressive therapy Severe malnutrition Types of Immune Suppression

3. Killed and Inactive DPT HIB IPV Pneumococcal Polysaccharide Conjugated Injected influenza Hepatitis A Hepatitis B Meningococcal Polysaccharide Conjugated Typhoid Live Measles Mumps Rubella Rotavirus Intranasal influenza Varicella Oral polio BCG Typhoid Yellow Fever Vaccinia Vaccines

4. Risk from Immunization in Immune Compromised Children • Limited data available for malignancy • Risk of adverse events in largely unknown • Data from HIV/AIDS • Relatively low risk of adverse reactions • When CD4 counts >15%

5. Live Vaccines • Both bacterial and viral • Contraindicated in severe immune deficiency • Make cause severe disease • Generally not effective • Benefit may outweigh risk in less than severe immune deficiency

6. Inactivated Vaccines • Use on schedule for immunecompromised • Risk of complications not increased • Immune response to vaccines may be poor • Secondary immune suppression • Key period is immune suppression within two weeks of immunization • After discontinuation of suppressive therapy normal response to vaccines in 3 to 12 months • Immune globulin should be given as appropriate • Measles prophylaxis should be given on exposure • Varicella—VZIG should be considered if available • Standard Hepatitis B, TIG, and HRIG indications

7. Influenza Vaccine • Should be given every year prior to influenza season for both primary and secondary immune deficiency • Age 6 months and older • Use inactivated vaccine only • Give no sooner than 3-4 weeks after end of a course of chemotherapy • Peripheral granulocyte and lymphocyte counts >1000 cells/l

8. Secondary (Acquired) Immunodeficiencies-HIV • BCG • Not recommended by WHO • Complications have been reported • Measles • Mortality as high as 40% • Do not need to test asymptomatic children • OK if CD4+ counts ≥ 15% • Give at 12 months and as soon as 28 days following first dose • Give at 6 months if outbreak • Varicella • Consider if CD4+ counts ≥ 15% • Inactivated vaccines should all be given according to the usual schedule • Passive immunoprophylaxis or chemoprophylaxis recommended even when vaccinated

9. Secondary Immunodeficiency-Cancer • If possible vaccinate prior to chemotherapy • Two weeks prior to initiation of therapy • Live vaccines are contraindicated • Minimum of three months after therapy is ended • Inactivated vaccines should be given according to schedule • Give during maintenance therapy with ANC and ALC>1000cells/l • Test 4-6 weeks following vaccination if available • Retest at one year after therapy discontinued or revaccinate with a booster • Consider delaying vaccine for three months if coming of therapy • Children at increased risk from these diseases • Vaccinate close contacts

10. Household Contacts • Smallpox and OPV contraindicated inhousehold contacts • MMR, varicella, rotavirus are OK in household contacts • Very low transmission rates • If rash with varicella, separate from patient • VZIG not indicated • Yearly inactivated influenza vaccination • Appropriate inactivated vaccines

11. Hematopoietic Stem Cell Recipients • May retain donor immunity • Donor immunity for inactivated vaccines • Vaccinate donor prior to transplant • Facilitated by immunization within five weeks of transplant for recipient • Studied for diphtheria and tetanus • Presumed similar for other inactivated vaccines • May test at 12 months to determine protection

12. HSCT Recipients--Live Viral Vaccines • May consider response to DPT as indicator of recovered immune response • Measles--Two years post HSCT • Second dose after 28 days • Don’t give if chronic GVHD • Varicella--data limited • Contraindicated <24 months after HSCT • >24 months by research protocol only • Give VZIG if exposed

13. HSCT Recipients--Inactive Vaccines • Influenza • May give >6 months but may not be effective until 12 months • Hepatitis B--limited data • Three doses starting at 12 months post HSCT • Doses at 12, 14 and 24 months • Follow-up serology • Polio • IPV starting at 12 months post HSCT • Doses at 12, 14 and 24 months • Hib and Pneumococcal Conjugate Vaccine • Start at 12 months post HSCT • Doses at 12, 14 and 24 months • Pneumococcal Polysaccaride • After 24 months, repeat in 12 months

14. Solid Organ Transplant Recipients • Give vaccines at least one month prior to transplant • May give measles vaccine as early as 6 months of age • No live vaccines after transplant • Use after 6 months on minimal immune suppressive therapy is being studied • Household contacts should be immunized • No live polio vaccine • Killed vaccines OK • Best after six months

15. Asplenia • High risk for: • Pneumococcal disease • HIB • Meningococcal disease • Vaccinate prior to surgery (14 days) • PVC 13 or polysaccharide vaccine • HIB conjugate • Tetravalent conjugated Meningococcal • As early as 2 years old

16. All Health Care Workers Should be fully immunized for: Polio, Pertussis Measles, Mumps, Rubella Varicella, Influenza Hepatitis A and B Health Care Workers