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Passive Immunization


Margot L. Savoy

, MD, MPH, Lewis Katz School of Medicine at Temple University

Last full review/revision Jun 2021| Content last modified Jun 2021
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Passive immunization involves giving

  • Antibodies to an organism or a toxin produced by an organism

Passive immunization is provided in the following circumstances:

  • When people cannot synthesize antibody

  • When people have been exposed to a disease that they are not immune to or that is likely to cause complications

  • When people have a disease and the effects of the toxin must be ameliorated

Passive immunization does not induce natural immunity.

For immune globulins and antitoxins available in the US, see Table: Immune Globulins and Antitoxins* Available in the US.


Immune Globulins and Antitoxins* Available in the US

Immunobiologic Agent



Botulinum antitoxin

Specific equine antibodies

Treatment of botulism

Botulinum antitoxin (BIG)

Specific human antibodies

Treatment of botulism in infants

Cytomegalovirus immune globulin, IV (CMV-IGIV)

Specific human antibodies

Diphtheria antitoxin

Specific equine antibodies

Treatment of respiratory diphtheria

Hepatitis B immune globulin (HBIG)

Specific human antibodies

Prophylaxis for hepatitis B postexposure

Immune globulin (IG)

Pooled human antibodies

Prophylaxis for hepatitis A preexposure and postexposure, measles postexposure, immunoglobulin deficiency, rubella during the 1st trimester of pregnancy, varicella (if varicella zoster immune globulin is unavailable)

Immune globulin, intravenous (IVIG)

Pooled human antibodies

Prophylaxis for graft-vs-host disease

Immune globulin, subcutaneous (SCIG)

Pooled human antibodies

Treatment of primary immunodeficiency disorders

Rabies immune globulin (HRIG)†

Specific human antibodies

Management of rabies postexposure in people not previously immunized with rabies vaccine

Respiratory syncytial virus murine monoclonal antibody (RSV-mAb)

Murine monoclonal antibody (palivizumab)

Prevention of RSV in high-risk infants

Tetanus immune globulin (TIG)

Specific human antibodies

Treatment of tetanus

Postexposure prophylaxis in people not adequately immunized with tetanus toxoid

Vaccinia immune globulin (VIG)

Specific human antibodies

Treatment of eczema vaccinatum, vaccinia necrosum, and ocular vaccinia

Varicella-zoster immune globulin (VariZIG)

Specific human antibodies

Postexposure prophylaxis in people who have no evidence of immunity, are at increased risk of severe varicella, and have contraindications to the varicella vaccine

* Immune globulin preparations and antitoxins are given intramuscularly unless otherwise indicated.

† Rabies immune globulin (HRIG) is given around wounds as well as intramuscularly.

Adapted from Ezeanolue E, Harriman K, Hunter P, et al: General best practice guidelines for immunization: Best practice guidance of the Advisory Committee on Immunization Practices (ACIP). Accessed on 03/04/2021.

Human immune globulin (IG)

IG is a concentrated antibody-containing solution prepared from plasma obtained from normal donors. It consists primarily of IgG, although trace amounts of IgA, IgM, and other serum proteins may be present. IG very rarely contains transmissible viruses (eg, hepatitis B or C, HIV) and is stable for many months if stored at 4° C. IG is given intramuscularly (IM).

Because maximal serum antibody levels may not occur until about 48 hours after IM injection, IG must be given as soon after exposure as possible. Half-life of IG in the circulation is about 3 weeks.

IG may be used for prophylaxis in people exposed to or at risk of

IG provides only temporary protection; the antibody content against specific agents varies by as much as 10-fold among preparations. Administration is painful, and anaphylaxis can occur.

IV immune globulin (IVIG) was developed to provide larger and repeated doses of human immune globulin. IVIG is used to treat or prevent severe bacterial and viral infections, autoimmune disorders, and immunodeficiency disorders, particularly the following:

Adverse effects of IVIG are uncommon, although fever, chills, headache, faintness, nausea, vomiting, hypersensitivity, anaphylactic reactions, coughing, and volume overload have occurred.

Subcutaneous immune globulin (SCIG) is also prepared from pooled human plasma; SCIG is intended for home use in patients with a primary immunodeficiency.

Injection site reactions are common, but systemic adverse effects (eg, fever, chills) are much less common with SCIG than with IVIG.

Hyperimmune globulin

Hyperimmune globulin is prepared from the plasma of people with high titers of antibody against a specific organism or antigen. It is derived from people convalescing from natural infections or donors artificially immunized.

Hyperimmune globulins are available for

Administration is painful, and anaphylaxis may occur. Hyperimmune globulin from patients recovered from COVID-19 is being used on an experimental basis.

Monoclonal antibodies

Specific monoclonal antibodies active against infectious agents are of great theoretical interest, and a number are currently being studied. However, only one product, palivizumab, is currently available; it is active against respiratory syncytial virus (RSV) and is used for prevention of RSV infection in certain high-risk children.

Drugs Mentioned In This Article

Drug Name Select Trade
Gammagard S/D
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