Dr. Athal Humo

transient Passive immunity is achieved by administration of preformed antibodies to induce transient protection against an infectious agent. Passive immunity also can be induced naturally through transplacental transfer of maternal antibodies (IgG) during gestation. Maternally derived transplacental antibodies can provide protection during an infant's first months of life

The major indications for passive immunity are to provide protection to: B-lymphocyte defects 1.immunodeficient children with B-lymphocyte defects who have difficulties making antibodies. exposed to infectious 2.persons exposed to infectious diseases or who are at imminent risk of exposure where there is no adequate time for them to develop an active immune response to a vaccine infectious disease 3.persons with an infectious disease as part of specific therapy for that disease.

IG is a sterile antibody-containing solution, usually derived from adult human plasma. Indication of IG: A.IG for i.m injection: 1.Replacement therapy in antibody deficiency disorders. 2.Hepatitis A prophylaxis 3.Measles prophylaxis

B. IG for i.v injection: 1.Replacement therapy in antibody deficiency disorders. 2.Kawasaki diseas 3.P ediatric HIV 4.Hypogammaglobulinemia in chronic B-cell lymphocytic leukemia 5.Bone marrow transplantation 6.May be useful in a variety of other conditions as Guillain-Barre syndrome, immune mediated thrombocytopenia, severe toxic shock syndrome …….

C. Other types of IG: Specific Immune Globulin Preparations: Specific Immune Globulin Preparations: Hyperimmune globulin preparations are derived from donors with high titers of antibodies to specific agents and designed to provide protection against those agents – Hepatitis B immune globulin (IM) – Rabies immune globulin (IM) – Tetanus immune globulin (IM) – Varicella-zoster immune globulin (VZIG) (IM) or IVIG Hyperimmune Animal Antisera Preparations: Hyperimmune Animal Antisera Preparations: Animal antisera preparations are derived from horses. 2 horse antisera preparations are available for humans: diphtheria antitoxin, which is used to treat diphtheria, and botulinum antitoxin. Great care must be exercised before administering animal-derived antisera because of the potential for severe allergic reactions. Monoclonal Antibodies: Monoclonal Antibodies: Monoclonal antibodies are antibody preparations produced against a single antigen. A major monoclonal antibody used in infectious diseases is palivizumab, which can prevent severe disease from respiratory syncytial virus (RSV) among children ≤24 mo of age with chronic lung disease, with a history of premature birth, with congenital heart lesions or with neuromuscular diseases.

Adverse reaction to IG IGIM: – Pain and discomfort at the injection site, less common flushing, headache, chills, and nausea – Rare & serious: chest pain, dyspnea, anaphylaxis, and systemic collapse. IGIV: – Fever, headache, myalgia, chills, nausea, and vomiting. thromboembolic disorders, aseptic meningitis, and renal insufficiency. – More serious reactions rarely have been reported, including anaphylactoid events, thromboembolic disorders, aseptic meningitis, and renal insufficiency.

Contraindications and special considerations: All vaccines: if there is severe allergic reaction (e.g., anaphylaxis) after a previous vaccine dose or to a vaccine component Live vaccines: –Immunosuppressed –Pregnancy

Immunosuppression fatal infections extensive replication Live vaccines can, in some situations, cause severe or fatal infections in immunosuppressed individuals due to extensive replication of the vaccine strain. severely For this reason, severely immunosuppressed individuals should not be given live vaccines.

The following individuals should not receive live vaccines: primary secondary 1.patients with evidence of severe primary immunodeficiency, e.g. SCI, or secondary as HIV infection. systemic high-dose steroids, 2.Patients receiving systemic high-dose steroids, until at least 1 months after treatment has stopped. This would include children who receive prednisolone, orally or rectally, at a daily dose (or its equivalent) of 2mg/kg/day for 2week, or 1mg/kg/day for one month. solid organ transplant 3.Patients who have received a solid organ transplant and are currently on immunosuppressive treatment. At least 3-6 months after stopping treatment.

chemotherapy or radiotherapy 4.Patients currently being treated for malignant disease with immunosuppressive chemotherapy or radiotherapy, or who have terminated such treatment within at least the last 6 months, and disease in remission. bone marrow transplant, 5.Patients who have received a bone marrow transplant, until at least 12 months after finishing all immunosuppressive treatment, or longer where the patient has developed graft-versus-host disease.

Pregnancy no evidenceThere is a theoretical concern that vaccinating pregnant women with live vaccines may infect the foetus. There is no evidence that any live vaccine (including rubella and MMR) causes birth defects. However, live vaccines should generally be delayed until after delivery. Termination of pregnancy following inadvertent immunization is not recommended

Contraindication & Precaution To Vaccine

Conditions are NOT contraindications to immunization 1.Mild acute illness ± fever. 2.Mild –moderate local reaction. 3.Family history of any adverse reactions following immunization. 4.Prematurity. 5.Stable neurological conditions such as well controled convulsion, cerebral palsy and Down’s syndrome. 6.History of other non vaccine allergic condition as hay fever, pencillin allergy, etc. … 7.Close contact of an immunosuppressed individual, except for OPV.

General Principles of Childhood Vaccination same day 1 mo apart. live-attenuated vaccines (MMR, varicella, LAIV) if not administered on the same day, should be given at least 1 mo apart. measles varicella IG does not interfere with killed vaccines. However, IG can interfere with the immune response to measles and varicella vaccine. Depending on the dose of IG received, MMR & var vaccine should be deferred for as long as 3-11 mo. not LAIVrotavirus IG is not expected to interfere with the immune response to LAIV or rotavirus vaccines.

Prematuresame schedule Premature infants should be kept on the same schedule as full-term infants. uncertain Children whose vaccination status is uncertain should be considered unimmunized and should be given appropriate vaccines.

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