Immunologic Medications Chapter 21 Immunologic Medications

Chapter 21 Lesson 21.1

Learning Objectives Define common terms used in immunology Explain the differences between the three different types of immunity Outline typical immunization plans for children and adults List the major adverse reactions of common immunologic drugs Identify at least three drugs used for in vivo testing

Immune System Antigen = a bacterium, virus, or foreign protein that invades the body Antibody = special proteins made by the body in response to sensing the foreign antigen Antigen-antibody response = a specific antigen causes the body to produce a specific antibody that reacts specifically with that antigen The lymphatic system and reticuloendothelial system respond to antigen invasion in the body by making antibodies. Antibodies are designed to help neutralize or resist the effects of the invading proteins (antigens). Some antibodies provide active immunity for the life of the person, others are active for a short period of time, providing passive immunity.

The Lymphatic System

Immunity Types of Immunity Naturally acquired active immunity: person has had the disease and made antibodies; antibodies remain for life Artificially acquired active immunity: person is given a live or weakened (attenuated) antigen in a vaccine to stimulate antibody production to prevent specific diseases for an extended time; “boosters” may be necessary There are different types of immunity. A person who has had chickenpox is said to have naturally acquired active immunity to that particular disease. The person who has had the disease has made lifelong antibodies against the disease to prevent its recurrence. The purpose of artificially acquired active immunity is to prevent the person from contracting dangerous diseases throughout his or her life. Rubeola (measles) is one of the vaccines given. Live vaccines are treated so the risk of developing a full infection in an otherwise healthy person is minimal. The rubeola vaccine does cause the person to develop a mild case of measles, which then initiates the antigen-antibody response in the body to prevent the person from getting a full infection from measles. Some diseases may require periodic booster injections of vaccine to maintain high enough antibody levels to protect the person from disease.

Immunity (cont.) Types of Immunity (cont.) Passive immunity Naturally acquired passive immunity Antibodies pass from mother to infant through breast milk Artificially acquired passive immunity Immunoglobulins are injected into a person who does not have immunity to the antigen After the antigen-antibody response has occurred, the antibodies are stored in the body. Immunoglobulins are specific types of protein antibodies that are stored in blood serum and plasma. Concentrated immunoglobulins are also called antiserums and may be collected from humans or animal sources. Administration of hepatitis B immune globulin to someone exposed to, but not immunized against, the disease is an example of artificially acquired passive immunity. Passive immunity is temporary.

Immunization Schedule The Following Vaccines Are Recommended: Hepatitis B Diphtheria, tetanus, pertussis Haemophilus influenzae type b Inactivated poliovirus Measles, mumps, rubella Varicella Pneumococcal Influenza Hepatitis A (for selected populations) Although most children in this country have received their immunizations before entering school, the United States lags behind many other countries in the percentage of children immunized at an early age. We now know that some of the early immunizations require “boosters” to provide lifelong immunity. The “MMR” booster for measles, mumps, and rubella is an example of this. The American Academy of Pediatrics, the Advisory Committee on Immunization Practices, and the American Academy of Family Physicians collaborate on immunization guidelines that are updated every January.

Immunologic Medications Vaccines = attenuated or killed antigens in a formula that produces an antigen-antibody response in the body Toxoids = attenuated or weakened toxins that produce an antitoxin response, causing immunity in the body Some disease-causing proteins that come from invading bacteria are called toxins. Toxins, like antigens, stimulate the immune system to produce antitoxins, which act to neutralize antigens. The body is unable to distinguish between a toxin and toxoid. What does the term endemic mean?

Immunologic Medications (cont.) Action Produce immunity in the body Uses Routine schedule of active immunizations for adults and children Specific biologic agents for endemic disease areas Specific biologic agents to people at high risk Screening for disease exposure Modify disease process in immunized persons There are many uses for immunologic medications. In addition to the routine administration of immunizations for specific diseases, immunizations are recommended for persons who live in areas with high risk of exposure to diseases such as yellow fever, cholera, and typhoid. People at high risk for serious complications of pneumococcal infections and influenza (e.g., elderly, chronically ill, healthcare workers) are encouraged to obtain these immunizations. An additional group of biologic agents (purified protein derivative [PPD], histoplasmin, coccidioidin) is used in screening procedures to identify persons who have been exposed to a certain disease or who may have the active disease (e.g., tuberculosis). In special circumstances, biologic agents such as gamma globulins may be useful for modifying a disease process in previously unimmunized persons.

Immunologic Medications (cont.) Adverse Reactions Mild reactions common: mild local pain and swelling at site Occasional effects include altered levels of consciousness, headache, lethargy, rash, urticaria, vesiculation, diarrhea, increased respiratory rate, arthralgia, dyspnea, fever, lymphadenopathy, and malaise. There are rare instances of these medications being linked to other health problems. Statistically, the risk of complications from getting disease outweighs the risk of adverse effects of the immunization. Occasional effects are treated symptomatically, and many physicians recommend premedication before receiving scheduled vaccines. Most states have laws that require infants and children to be properly immunized before starting school. To reduce the liability pharmaceutical companies face, a special fund has been established by the federal government that pays for medical costs incurred if a patient has a serious adverse effect from required immunizations. A certain percentage of fees patients pay go toward this fund, called the National Vaccine Injury Compensation Program.

Immunologic Medications (cont.) Drug Interactions Nursing Implications and Patient Teaching Assess health history, immunization status, allergies to eggs or feathers, presence of infection, use of immunosuppressants, pregnancy Some vaccines are contraindicated in persons with an allergy to eggs or feathers, because they are prepared with animal serum or in chick embryos. Immunizations are not given to patients with active infection, severe febrile illness, or a history of serious side effects from previous vaccinations. Live, attenuated virus vaccines should not be given if there is a recent history of acquired passive antibodies (immune globulins). Patients who are immunocompromised should not be given immunologic agents, and all vaccines should be used with caution in women who are pregnant or breastfeeding.