Immunoprophylaxis

Immunoprophylaxis - Immunoprophylaxix Immunoprophylaxix...

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Unformatted text preview: Immunoprophylaxix Immunoprophylaxix Protection against infectious diseases by (immunization) acquired by the individual either passively or actively: I­ Passive acquired immunity II­ Active acquired immunity I- Passive acquired immunity IReady made Ab transferred to individual giving rapid protection and short lasting immunity: a­Naturally acquired passive immunity Occurs when antibody are transferred from mother to fetus ( IgG ) or in colostrum (Ig A). b­ Artificially acquired passive immunity Short­term immunization by injection of antibodies, For examples: ­ injection of antitoxic serum for treatment of diphtheria or tetanus. ­ injection of gamma globulin that are not produced by recipient's cells, to hypogammaglobulin children. II- Active acquired immunity II Individual actively produces his own Ab. Immunity develop slowly and long lasting due to development of immunological memory: a­Natural active acquired immunity The person becomes immune as a result of previous exposure to a live pathogen b­Artificially active acquired immunity A vaccine stimulates a primary response against the antigen without causing symptoms of the disease. Vaccination Vaccination ­immunity against pathogens (viruses and bacteria) by using: live attenuated killed altered antigens that stimulate the body to produce antibodies ­Vaccines work with the immune system's ability to recognize and destroy foreign proteins (antigens) Vaccination Vaccination Vaccination prevents and control such diseases as cholera, rabies, poliomyelitis, diphtheria, tetanus, measles, and typhoid fever Vaccines can be: a­ prophylactic (e.g. to prevent or ameliorate the effects of a future infection by any natural or "wild" pathogen b­ Therapeutic (e.g. vaccines against cancer are also being investigated Types of vaccines: Types 1­Killed vaccines: Virulent bacteria or viruss used to prepare these vaccines may be killed by heat (60 °C) or by chemicals (formalin, phenol or merthiolate), examples: a­TAB vaccine against entric fever (heat) b­Salk vaccine against poliomylitis (formaline) c­Semples vaccine against rabies (phenol) d­pertussis vaccine against whooping cough (merthiolate) Types of vaccines: Types Killed vaccine are: Do not stimulate local immunity Short lasting Do not stimulate cytotoxic T cell response in contrast to live attenuated vaccines safe can be given to pregnant woman and immunocompromised host Types of vaccines: Types 2­live attenuated vaccines: ­ living m.o lost its virulence so do not produce disease but produce immunity. ­stimulate both humoral and cell mediated immunity, local and systemic. ­not given to pregnant women and immunocompromised hosts (may cause diseases) ­heat unstable Types of vaccines: Types ­ It is prepared by: a­repeated subculture in unsuitable condition (chemical or media) e.g BCG vaccine against T.B and 17 D vaccine against yellow fever. b­growing at high temp. (above optimum temp) e.g Pasteur anthrax vaccine c­selection of mutant strains of low virulence e.g Sabin vaccine against poliomylitis. Types of vaccines: Types 3­ Toxoids ­ ­ ­ It is prepared by detoxifying bacterial toxins. bacterial exotoxins treated by formaluin to destroy toxicity and retain antigenicity e.g.diphtheria and tetanus toxoid. Types of vaccines: Types 4­ Microbial products vaccines are prepared from bacterial products or viral components e. g: a­Capsular polysaccharide vaccines are: ­ Poor immunogen in children below 2 years age e. g H. influenza ­do not respond to T cell independent antigens inspite of its generation of Ig M ­produce anticapsular opsonizing antibodies ­examples meningiococci, pneumococci and H. influenza b­cellular purified proteins of pertussis c­ purified surface Ag of hepatitis B virus d­influenza viruses Types of vaccines: Types prepared by recombinant DNA technology for improvement vaccines e.g: a­ subunit vaccines in which microbial polypeptides are isolated from the infective material hepatitis B and influenza viruses B­ Recombinant DNA­derived antigen vaccines: in which Ag are synthesizing by inserting the coding genes into E. coli or yeast cell as HBV vaccines C­ Recombinant DNA avirulent vector vaccines: in which the genes coding for the Ag is inserted into genome of an avirulent vector such as BCG vaccine D­Synthetic peptide vaccines: synthesis of short peptides that corrospond to antigenic determinants on a viral or bacterial proteins e.g cholera toxins and poliovirus to produce Ab response. Combined immunization (Vaccination) Combined ­Immunization against diseases is recommended in combination (for young children) as : diphtheria, tetanus (lockjaw), and pertussis ( whooping cough), given together (DTP). measles, mumps, and rubella, give together as MMR Haemophilus influenzae b (Hib) with DTP influenzae b (Hib) with inactivated poliomyelitis vaccine (IPV) influenza; and Neisseria meningitidis (meningococcal meningitis). ...
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This note was uploaded on 12/21/2011 for the course STEP 1 taught by Professor Dr.aslam during the Fall '11 term at Montgomery College.

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