Immunization of the immunocompromised child: key principles Flashcards
Why is immunization important for children who are immunosuppressed?
Increased risk for severe disease from vaccine preventable disease
Goal to provide maximum protection while minimizing harm
What is an online resource practitioners can refer to resource on immunizations?
The Canadian Immunization Guide
How can “indirect protection” be provided to immunocompromised patients?
Household vaccination of family members ( ie: yearly flu shot and routine vaccinations)
- Vaccinate pets!
Are inactivated vaccines safe to give to this population? Are there any other considerations?
Inactivated vaccines are safe
- Immune response may be diminished or absent thus increased in dose or number of doses may be indicated
(ex: hepatitis B, conjugated pneumoccocal vaccines)
Why are live vaccines contraindicated among immunocompromised patients?
May cause disease by uncontrolled replication and are usually contraindicated
What are exceptions to the no live vaccine rule?
Isolated IgA deficiency IgG subclass deficiency Complement deficiency Anatomical or functional asplenia HIV** when NOT severely immunocompromised
Children with phagocyte or neutrophil disorders (including chronic granulomatous disease) can have live viral vaccines BUT NOT live bacterial vaccines such as BCG or live typhoid vaccine
List two examples of live vaccines
Rotavirus
MMRV
BCG
Live typhoid vaccine
What additional vaccines may an immunocompromised child require?
- May require additional vaccines ex: 23-valent pneumoccocal polysaccharide
- May require additional doses of vaccine (such as Haemophilus influenzae Type B)
- May require boosters due to waning immune respones ex: Hep B boosters
Why should timing be considered when planning immunization?
Should be given when maximum immune response can be anticipated
Ex: If disease process leads to immune deterioration over time (ex: HIV, congenital immunodeficiency)
Ex: if immunosuppression is planned (ex: organ transplantation, starting steroids)
If time permits before planned immunosuppression, how should vaccines be administered?
- Provide all live and inactivated vaccines prior to immunosuppression
- Inactivated vaccines should be given TWO WEEKS before planned immunosuppression
- Live vaccines should be given FOUR WEEKS before planned immunosuppression
- Measles, mumps, rubella, varicella can be given as early as 6 months for solids organ transplant candidates if needed
If immunosuppression is urgent but temporary, how should vaccines be given?
- Defer immunization until the immune system as recovered
If risk of exposure to specific infection is high, inactivated vaccine may be given though response is likely to be diminished
How long after high dose steroid therapy can live vaccines be given?
1 month
How long after the completion of immunosuppressive chemotherapy can live vaccines be given?
3 months
How long after treatment with anti-B cell antibodies can live vaccines be given?
6 months
How dose of steroids is considered “high dose” and immunosuppressive?
High dose steroid therapy is defined as systemic treatment with:
- The equivalent of prednisone ≥2 mg/kg/day or ≥20 mg/day if weight >10 kg for ≥14 days
Are live vaccines contraindicated for lower dose steroids or with shorter treatment course?
No!
Why is immunization after HSCT complicated?
No longer considered to be immune to conditions for which they received vaccines pre-transplant
Which vaccines do you require after HSCT?
Require re-immunization with ALL routine vaccines
When can reimmunization with inactivated vaccines be started after HSCT?
- 3-12 months post
When can reimmunization with live vaccines be started after HSCT?
24 months post transplant*
*Contingent on- no evidence of chronic graft versus host disease, immunosuppression has been discontinued for at least 3 months, and the transplant specialist considers the patient to be immunocompetent
When can inactivated vaccines be given in the case of anticipated long term immunosuppression?
- When the patient is on the lowest anticipated dose of immunosuppressive agents
- If* feasible, ideally would hold or reduce dose of immunosuppressive agent temporarily to maximize respsonse
When should recipients of solid organ transplants receive inactivated vaccines?
- 3 to 6 months post transplant if baseline immunosuppressive levels are attained
Can live vaccines be given to the recipient of a live organ transplant?
Generally no*
*Only extenuating circumstances in consultation with transplant expert
Can donors of hematopoietic stems cells and solid organs receive vaccines?
Yes!
*Parenteral live vaccines should be avoided for 4 weeks prior to stem cell or organ harvest
