Definition of Immunization – This book covers the entire syllabus of “Community Health Nursing” prescribed by the Universities of Bangladesh- for Basic and diploma nursing students. We tried to accommodate latest information and topics.
This book is examination friendly setup according to the teachers’ lectures and examination’s questions. At the end of the book previous university questions are given. We hope in touch with the book students’ knowledge will be upgraded and flourished. The unique way of presentation may make your reading of the book a pleasurable experience.
Definition of Immunization
Concepts:
Immunization is the process of introducing some form of disease-causing organism into a person’s system in order to cause the development of antibodies that well resist that disease. A global immunization program known as expanded programme on immunization (EPI) aims to protect all children of the world against six vaccine preventable diseases, namely -Diphtheria, whooping cough, tetanus, polio, tuberculosis and measles. To make EPI a success the activities for achieving universal child immunization in accordance with 4-point action programme should be adopted in Bangladesh depending upon the need and conditions: promotion EPI within the context of primary health care, investment of adequate human resources for EPI, investment of adequate financial resources for EPI and immunization coverage monitoring.
Immunity/ Host defense against infection
Immunity is the ability of the body to recognize, destroy & eliminate antigenic material (bacteria, viruses, proteins, etc), which is foreign to its own.
Or
Immunity the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.
Or
In biology, immunity is the balanced state of multicellular organisms having adequate biological defenses to fight infection, disease, or other unwanted biological invasion, while having adequate tolerance to avoid allergy, and autoimmune diseases.
Types of immunity
Immunity can be described as either active or passive, depending on how it is acquired:
1. Active immunity: Active immunity involves the production of antibodies by the body itself and the subsequent development of memory cells.
Examples of Active Immunity
- a) Natural – Producing antibodies in response to exposure to a pathogenic infection (i.e. challenge and response)
- b) Artificial Producing antibodies in response to the controlled exposure to an attenuated pathogen (i.e. vaccination)
2. Passive immunity: Passive immunity results from the acquisition of antibodies from another source and hence memory cells are not developed.
Examples of Passive Immunity
a) Natural Receiving antibodies from another organism (e.g. to the foetus via the colostrum or a newborn via breast milk)
b) Artificial Receiving manufactured antibodies via external delivery (e.g blood transfusions of monoclonal antibodies)
Active immunity will result in long-term immunity but passive immunity will not (due to the presence or absence of memory cells)
Both active and passive immunity can be induced by either natural or artificial mechanisms.
Active immunity is superior to passive immunity due to-
➤ Protection is long lasting
➤ No risk of hypersensitivity reaction
➤ Develop immunological memory
➤ Less expensive
➤ More effectiveness
➤ Mild side effects
➤ Prevention of disease
Host resistance against infections
Active immunity:
➤ It is that type of acquired immunity where immune competent cells of body participate actively.
➤ It is the immunity which is developed in an individual as a result of infection or specific immunization.
➤ Here the individual produces actively the antibodies or effectors T cell after contact with foreign antigen.
Active immunity may be acquired in 3 ways:
a) Following clinical infection e.g. /Chicken pox, /Rubella / Measles.
b) Following subclinical or inapparent infection e.g. Polio & Diphtheria.
c) Following immunization with an antigen may be / Killed vaccine /a live attenuated vaccine or toxoid.
Passive immunity:-
When antibodies produced in one body are transferred to another to induce protection against disease. It is known as passive immunity.
Or
It is that type of acquired immunity where the antibody is introduced into a host to produce a specific immunity
Passive immunity may be developed in following ways
- By administration of antibodies containing preparation (Immunoglobulin or antiserum)
- By transfer of maternal antibodies across the placenta.
- By transfer of maternal antibodies (IGA) via colostrum to foetus.
- By transfer of lymphocytes, to induces passive cellular immunity.
Immunoglobulins
Immunoglobulins are glycoproteins of structural similarities with or without antibody like activity.
Or
These are proteins of animal origin endowed with or without antibody activity
Antigen:
An antigen is a substance protein or polysaccharide in nature which when introduced into the body is capable of inducing an immune, response leading to formation of antibodies with which it react specifically.
Antibody:
Antibodies are immunoglobulin that react specifically with the antigen that stimulate their production. -IgG, IgM. IgD, IgA. IgE.
Functions of immunoglobulins
IgG:
➤ Cross the placenta & produce natural passive immunity in newborns.
➤ Neutralization of bacterial toxin & virus.
➤ Complement activation.
➤ Most effective antibody in secondary response.
Ig M:
➤ Very effective complement fixator.
➤ Very effective agglutinators.
➤ Produce early immune response
➤Effective first line defense
Ig A:
➤Prevents attachment of bacteria & virus to mucous membrane.
➤ Antiviral activity.
Ig D:
➤ Present in B cell surface & act as a receptor.
➤Involve in lymphocytic differentiation.
IG E:
➤ Mediates type-1 hypersensivity reaction (Anaphylactive reaction)
➤ Provide-defense against parasitic infections.
Immune response
Development of resistance (immunity) to foreign substance is called immune response.
Type:
a) Primary IR
b) Secondary IR
Primary immune response:
Primary immune response is the immune response that occurs on first exposure to any antigen.
Primary immune response is characterized by –
a) Long lag phase
b) IgM-predominant Ig class.
c) Low titer of antibody with low quality and short duration.
Secondary immune response:
Secondary immune response occurs following subsequent exposure.
Secondary immune response is characterized by –
- Short lag phase
- IgG-predominant Ig class.
- High titer of antibody with High quality and Long duration.
- Memory cells present.
Difference between active immunity and passive immunity
| Traits | Active immunity | Passive immunity |
| i) Definition | It is that type of acquired immunity where immune-competent cells of body participate actively. | It is that type of acquired immunity where immune-competent cells of body participate actively. It is that type of acquired immunity where the antibody is introduced into a host to produce a specific immunity |
| ii) Involvement of B & T cells. | Yes | No |
| iii) Onset | It takes 1-3 wk’s for the immunity to developm | Immunity is rapidly established |
| iv) Duration | Immunity may persists for years or lifelong | Immunity induced lasts for short time. (few wk’s only) |
| v) Immunological memory | Develop | Does not develop |
| vi) Use | Prevention of disease | Prevention with treatment of disease. |
| vii) Effectiveness | More | Less. |
| viii) Cost effectiveness | Less expensive | More expensive. |
| ix.)Hypersensitivity. | No develop | Risk of develop. |
| x) Transfer to foetus or breast fed child | Does | Does not |
| xi) Side effects | Mild | Serious |
| xii) Component | Cell mediated & humoral immunity | Humoral immunity |
| xiii) Application | Vaccination | Immune deficiency prophylaxis |
Immunization and vaccination
Definition of immunization
Immunization is the process of introducing some form of disease causing organism into a person’s system in order to cause the development of antibodies that well resist that disease.
Vaccination
Injection of a killed microbe in order to stimulate the immune system against the microbe, thereby preventing disease. Vaccinations, or immunizations, work by stimulating the immune system, the natural disease-fighting system of the body.
Immunizing agents
Some agents when introduced into the body produce immunity. These agents are called immunizing agents.
Classification
- Active immunizing agent: Vaccine.
- Passive immunizing agent: Immunoglobulins: Antisera.
Vaccine
Vaccine is defined as immunobiological substances which when introduced into the body are capable of producing antibody that is specific to that substance.
Or
A vaccine is a biological preparation that provides active acquired immunity to a particular disease. Vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
Types
a) Live attenuated vaccine(LAV)
b) Inactivated or killed vaccine.
c) Toxoid.
d) Extracted cellular fraction
e) Combination
Recent preparation are
a) Sub unit vaccine.
b) Recombinant vaccine.
1) LAV (Live attenuated vaccine)
Bacterial:
- BCG vaccine- TB.
- Typhoid oral
- Plaque.
Viral:
- Oral polio poliomyelitis
- Yellow fever.
- Rubella
- Mumps
- Influenza
Rickettsial:
- Epidemic typhus
2) Inactivated or killed vaccine
Bacterial:
- Pertusis vaccine – W. cough
- Cholera vaccine -Cholera
- Typhoid
- Plague
Viral:
- Salk vaccine (Polio)
- Rabies.
- Influenza.
- Hepatitis B
3) Toxoid
Bacterial:
- Tetanus toxoid- tetanus
- Diptheria toxoid- diptheria
4) Extracted cellular fraction
- Meningococal vaccine.
- Pneumococal vaccine
5) Combination
- DPT
✓ Diphtheria
✓Pertusis
✓ Tetanus
- MMR-Measles Mumps Rubella. DT.
- DP.
- DPT with typhoid vaccine DPTP (DPT + inactivated polio).
Live vaccine is more potent than killed vaccine because-
1. Live organisms multiply in the host and the resulting antigenic dose is larger than what is injected.
2. Live vaccines have all the major and minor antigenic components.
3. Live vaccines engage certain tissues of the body. e.g. intestinal mucosa by OPV. 4. There may be other mechanisms such as the persistence of latent virus.
Hazards of immunization
Reaction inherent to inoculation:
It may be i) Local reactions ii) General reactions.
i) Local Reaction:
- Pain
- Swelling
- Tenderness
- Small nodules.
- Sterile abscess.
ii) General reaction:
- Fever.
- Anorexia
- Malaise
- Headache
Reaction due to faulty techniques:
No immunity (inadequate inactivation’s of microbe).
- Hepatitis -B.
- Strepto and staphylococcal.
- Local abscess
Reaction due to hypersensivity:
➤ Anaphylactic shock :
✓ Bronchospasm
✓ Dyspnea
✓ Pallor
✓ Hypotension
✓ Collapse
➤ Serum sickness :
✓ Fever.
✓ Rash
✓ Oedema
✓ Joint pain antiserum-(ATS)
Neurological involvement:
➤ Post vaccinial encephalitis with encephalopathy- Antirabies & small pox vaccine.
➤ Guillain-Barre-Syndrome-Swine influenza vaccine.
- Provocative reaction:
➤ Diphtheria vaccine (APT or DTAP)- Causes-Polio.
➤ Polio vaccine causes measles.
Others:
➤ Rubella vaccine cause foetal damage.
See More: