1. Immunization/Vaccination
The term vaccination derived from the work of Edward Jenner (1796), induced immunity to small box.
He obtained fluid from skin lesion of cows who infected with cowpox and inoculating it into a boy to provide production against small box
Vaccination= Vacca=Cow
The concept of vaccination was expanded by Louis Pasteur ( ) – developed vaccines against cholera (Vibrio cholera) and rabies.

2. Active: administration of vaccine or antigens, to provide the individual with long-lasting immunologic protection against exposure to infections.
Natural: drinking of contaminated water or exposure to infection
Artificial : administration of a vaccine
Passive: administration of antibodies or lymphocytes to provide transient protection against infection.
Natural :breast milk feeding contain antibodies provide protection to the baby
Artificial; administration of immunoglobulin for immunodeficiency patients

3. Post exposure immunization
Post exposure immunization :an individual exposed to rabies virus can be protected against this infection by administration of both vaccine and immune globulin against rabies virus.
Use of toxoid and antitoxin against diphtheria,
vaccination against tetanus toxoid after trauma.
Administration of immunoglobulin against Hep A, B after infection.

4. Active Immunization example composition Vaccine type Typhoid
Entire organism, harmless
Killed whole organisms
Bacilli Calmette-Guerin (BCG),
Cultured or mutated
Attenuated bacteria
Diphtheria toxin, tetanus
Bacterial toxin treated to denature the protein
toxoids
Hemagglutinin, from influenza virus
Isolated from pathogen
Surface molecules
Sabin oral polio vaccine, measles, mumps
weaken virus
Attenuated virus

5. Features of effective vaccines
Safe
Protective
Gives sustained protection
Induces neutralizing antibodies
Induces protective T cells
Low cost, biological stability, ease of administration, few side effect

6. Basic Mechanism of protection are affected by several factors
1-Incubation period of infection: Repeated infection may provide the host with protection. -Long incubation period of a pathogen provide the host with protection, whereas short incubation period <3 days may not give protection to the host,after second exposure. 2-nutritional status and disease (which effect of Abs levels and cell-mediated immunity. 3-Age: At birth: maternal Abs are detected in the newborn, and are providing protection for the baby. For example: Maternal measles antibodies and interfere with vaccine, so vaccination is delayed until 1 year of age. some vaccine delayed upto 2month of age to avoid tolerance to this infection. At 60 years age; reduced response to Ags.

8. Precautions
Site of administration of vaccines: parenteral (intradermal, subcutaneous, intramuscular): The parenteral administration of polio vaccines induce more antibodies but oral administration affords adequate protection.
Hazards: attenuated vaccines, (measles, rubella ) have the potential to cause progressive diseases in immunocompromise patients.
Killed vaccines such as Bordetella pertussis in DTP associated with side effect (encephalopathy).
Vaccines should be monitored carefully.

9. Production of vaccines
1-Conjugated vaccines have been developed as a results of understanding how T and B cells collaborates in an immune response: encapsulated bacteria required antibodies for opsinization. Child <2years, cannot make antibodies (T cell independent) and can not be vaccinated with this antigen. Conjugation of polysaccharide to a protein such as tetanus or diphtheria toxoid elicits strong immune response.

10. 2-Live-attenuated viral vaccines are usually more potent than killed vaccines and can be safer by using recombinant DNA Technology:
- attenuation can be achieved by growing the virus in cultured cells. Although attenuated viral vaccines contain mutation in genes encodes their proteins, reversion may occur, and also not safe for immunodeficient recipient. Recombinant DNA technology are used, and mutated genes are replaced into to the wild type genes.
3- Synthetic peptides of protective antigens can elicit protective immunity.

11. Anti-idiotype vaccines: an antibody induced to a specific epitope of an antigen has a combining site fits the epitope (idiotype). If this idiotype is used as antigen, will generate anti-idiotype antibodies that mimics the epitope (internal image, because resemblance of original antigen epitope).This internal image of the antigen can be used as a vaccine for that particular antigen.
Virus/ bacterium- carrier vaccine. Carry an antigen-gene to elicit protective immunity.

12. attenuated
lower (agent replicates in the body)
Inactivated
higher (greater mass required
cost
oral
parenteral
administration 
not needed
needed
adjuvant
poor
good 
stability
possible
absent
reversion
antibody-mediate and cytotoxic T cells, long-lasting
antibody-mediated
short-lasting
 immunity

13. Passive Immunization: Differ than active immunization in that does not rely on the ability of the host to make appropriate response.
- passive immunization through placental: antibody transfer.
- Breast Milk contain antibodies such as IgA provide protection the baby.
-passive antibody therapy and serum therapy: administration of antibody/serum (from individual recovered from infection).
- Cytokine therapy