Body defense immunity & immunization

Nursing Foundation Unit I

1. Body defence immunity & Immunization Mr. Melvin Jacob MSc Nursing 1 11-11-2020 Mr.Melvin Jacob MSc (N)

2. INTRODUCTION The environment contains a wide variety of potentially harmful organisms (pathogens), such as bacteria, viruses, fungi, protozoa and multi cellular parasites, which will cause disease if they enter the body and are allowed to multiply. The body protects itself through a various defence mechanisms to physically prevent pathogens from entering the body or to kill them if they do. 2 11-11-2020 Mr.Melvin Jacob MSc (N)

3. IMMUNITY The term immunity refers to the body’s specific protective response to an invading foreign agent or organism. The human body has the ability to resist almost all types of organisms or toxins that tend to damage the tissues and organs. The capability is called immunity. 3 11-11-2020 Mr.Melvin Jacob MSc (N)

4. TYPES OF IMMUNITY 1 . Natural (Innate) immunity 2. Acquired (adaptive) immunity 4 11-11-2020 Mr.Melvin Jacob MSc (N)

5. I. Natural immunity It is a nonspecific immunity present at birth It is the ability to distinguish between friend and foe or self and non-self . Such natural mechanisms include 1. Physical and chemical barriers – Skin and mucous membrane – Antimicrobial substance in body secretions 2. The action of WBCs 3. Inflammatory response. 5 11-11-2020 Mr.Melvin Jacob MSc (N)

6. Physical and chemical barriers Skin and mucous membrane Intact skin & mucous membrane - physical barrier to invading microbes . Sebum and sweat secretion - contains antibacterial and antifungal substances Hairs in the nose acts as a coarse filter. One way flow of urine from the bladder during micturation 6 11-11-2020 Mr.Melvin Jacob MSc (N)

7. Antimicrobial substance in body secretions 1. Hydrochloric acid in gastric juice 2. Lysosomes 3. Saliva 4. Immunoglobulin in nasal secretions and saliva ( IgG , IgA , IgM , IgD and IgE , which have a range of functions .)   7 11-11-2020 Mr.Melvin Jacob MSc (N)

8. Inflammatory response • Major function of the natural immune system. • Chemical mediators assist this response by minimizing blood loss, walling off the invading organism, activating phagocytes and promoting formation of fibrous scar tissue and regeneration of injured tissue 8 11-11-2020 Mr.Melvin Jacob MSc (N)

9. Dysfunction of the natural immune system • Immunodeficiency • Persistent inflammatory response • Autoimmune bodies 9 11-11-2020 Mr.Melvin Jacob MSc (N)

10. II. Acquired immunity • Usually develops as a result of prior exposure to an antigen through immunization or by contracting a disease. • Weeks or months after exposure to the disease or vaccine, the body produces an immune response that is sufficient to defend against the disease upon re-exposure to it. 10 11-11-2020 Mr.Melvin Jacob MSc (N)

11. Active and passive immunity 1 . Active immunity: Active immunity means that the individual has responded to an antigen and produced his own antibodies, lymphocytes are activated and the memory cells formed provide long lasting resistance. 2. Passive immunity: In passive immunity the individual is given antibodies produced by someone else 11 11-11-2020 Mr.Melvin Jacob MSc (N)

12. Types of immunoglobulin 12 11-11-2020 Mr.Melvin Jacob MSc (N)

13. IgG IgG (75% of total immunoglobulin) • Appears in serum and tissues (interstitial fluid) • Assumes a major role in blood borne and tissue infections . • Activates the complement system . • Crosses the placenta 13 11-11-2020 Mr.Melvin Jacob MSc (N)

14. IgA IgA (15% of total immunoglobulins ) • Appears in body fluids (blood, saliva, tears, breast milk, and pulmonary, gastrointestinal, and vaginal secretions). • Protection against respiratory, gastrointestinal and genitourinary infections. • Prevents absorption of antigens from food. • Passes to neonate in breast milk for protection 14 11-11-2020 Mr.Melvin Jacob MSc (N)

15. IgM IgM (10% of total immunoglobulins ) • Appears mostly in intravascular serum • Appears as the first immunoglobulin produced in response to bacterial and viral infections. • Activates the complement system. 15 11-11-2020 Mr.Melvin Jacob MSc (N)

16. IgD IgD (0.2% of immunoglobulins ) • Appears in small amounts in serum • Possibly influences B-lymphocytes differentiation, but role is unclear. IgE IgE (0.004% of immunoglobulins ) • Appears in serum • Takes part in allergic and hypersensitivity of reactions • Combats parasitic infections. 16 11-11-2020 Mr.Melvin Jacob MSc (N)

17. Line of defence P revents infection through a number of non-specific and specific mechanisms working on their own or together. First lines of defence are external barriers that prevent germs from entering. Skin which acts as a strong, waterproof, physical barrier and very few organisms are able to penetrate undamaged skin.  17 11-11-2020 Mr.Melvin Jacob MSc (N)

18. Skin  - a strong physical barrier, like a waterproof wall Mucus  – a sticky trap secreted by all the surfaces inside the body that are directly linked to the outside, also contains antibodies and enzymes Cilia  – microscopic hairs in the airways that move to pass debris and mucus up away from the lungs 18 11-11-2020 Mr.Melvin Jacob MSc (N)

19. Lysozyme  – a chemical (enzyme) present in tears and mucus that damages bacteria Acid  - in stomach and urine, make it hard for any germs to survive Fever  – elevated body temperature making conditions unfavourable for pathogens to survive 19 11-11-2020 Mr.Melvin Jacob MSc (N)

20. Immunization Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease. 20 11-11-2020 Mr.Melvin Jacob MSc (N)

21. Protect us from serious diseases   Prevent the spread of those diseases Epidemics of once common infectious diseases such as measles, mumps, and whooping cough. 21 11-11-2020 Mr.Melvin Jacob MSc (N)

22. The recommended immunizations for children 0-6 years of age Hepatitis B Rotavirus Diphtheria, tetanus,  pertussis (DPT) Haemophilus influenzae  type B Pneumococcal Poliovirus Influenza Measles, mumps, rubella Varicella (chickenpox) Hepatitis A Meningococcal (for certain high-risk groups) 22 11-11-2020 Mr.Melvin Jacob MSc (N)

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25. Reference Dougherty L, Lister S (2015) The Royal Marsden Hospital Manual of Clinical Nursing Procedures. Oxford: Blackwell. Helen Harkreader . Fundamentals of nursing caring and clinical judgement. Elsevier publication St. Louis: 2009;(3). 25 11-11-2020 Mr.Melvin Jacob MSc (N)

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