Active and passive immunisation.pptx

Active and passive immunisation

1. Active and passive Immunisation Shinil lenin 403

2. Immunity The state of being immune from or insusceptible to a particular disease . I mm un e Sys t e m Respons e t o A n ti gen s: A. Humoral Immunity Involves antibodies (secreted from B cells) dissolved in the blood plasma. Demonstrated as a immune response using only the blood serum. Defense against bacteria, bacterial toxins, & viruses . B. Cell-Mediated Immunity Involves the activities of specific white blood cells (T cells). Defense against cancer cells, virus-infected cells, fungi, animal parasites, & foreign cells from transplants.

3. T yp e s o f Imm unit y

4. An infection is an example of acquiring natural immunity. It is called ACTIVE as your body needs to work to produce the necessary antibodies When a mother breast feeds her baby she passes antibodies to it. This is a way of acquiring PASSIVE immunity as it is a way of gaining antibodies without the immune system having to produce them. The thick, yellowish milk (colostrum) that is produced for the first few days after birth is particularly rich in antibodies. Na tu ra l i mm unit y : ac tiv e a n d p a ssiv e

5. Ar ti f i c i a l i mm uni t y : ac tiv e a n d p a ssiv e An alternative to natural immunity developing is to give vaccinations (artificial immunity) Antigen is injected into the body. This may be in the form of an inactivated bacterial toxin or attenuated (not harmful) virus which would promote ACTIVE immunity; or the injection of antibodies or antitoxins which would promote PASSIVE immunity (eg Clostridium tetani )

6. The production of antibodies against a specific disease by the immune system. Naturally acquired through disease Artificially acquired through vaccination Vaccines include inactivated toxins, killed microbes, parts of microbes, and viable but weakened microbes. Memory T cells are only produced in active immunity. Protection for active immunity is permanent whereas in passive immunity it is only temporary. Antigens are only encountered in active immunity. Active immunity takes several weeks to become active but passive is immediate Act i v e I mmun i t y

7. A vaccinated person has a secondary response based on memory cells when encountering the specific pathogen. Routine immunization against infectious diseases such as measles and whooping cough, and has led to the eradication of smallpox, a viral disease. Unfortunately, not all infectious agents are easily managed by vaccination. HIV vaccine in the works

8. Passive Immunity- Protection against disease through antibodies produced by another human being or animal . Ex. Maternal antibodies , Colostrum Passive immunity doesn’t last as long as active immunity (only weeks or months): No lymphocytes are stimulated to clone themselves No memory cells have been made Effective, but temporary as this type of immunity can only last as long as the antibodies/toxins last in the blood Pass i v e I mmun i t y

9. Passive immunity can be transferred artificially by injecting antibodies from an animal that is already immune to a disease into another animal. Rabies treatment: injection with antibodies against rabies virus that are both passive immunizations (the immediate fight) and active immunizations (longer term defense).

10. Immunisation Immunisation is the process of becoming immune to a disease as a result of a vaccine . Vaccines take time to work, because your immune system needs time to produce an immune response to the vaccine. Some vaccines work after one dose, but others require more doses to be effective, and for some you need a ‘booster’ after a certain period, to restore your immunity to disease, which can lessen over time .

11. Vaccines used for immunisation

12. Vaccination Vaccination is a method of giving antigen to stimulate the immune response through active immunization. A vaccine is an immuno-biological substance designed to produce specific protection against a given disease. A vaccine is “antigenic” but not “pathogenic”. One of the most effective «weapons» in medicine 1798 Edward Jenner immunizes first time against smallpox 1885 Louis Pasteur prepares the 1st vaccine against Rabbies 1927 BCG (bacillus Galmette-Guerin) 1955 Salk vaccine against poliomyelitis 1960 MMR (Measles, Mumps and Rubella)……..

13. T yp e s o f v acc in e s Live vaccines Attenuated live vaccines Inactivated (killed vaccines) Toxoids Polysaccharide and polypeptide (cellular fraction) vaccines Surface antigen (recombinant) vaccines

14. L iv e va cc i ne s Live vaccines are made from live infectious agents without any amendment. The only live vaccine is “Variola ” small pox vaccine , made of live vaccinia cow-pox virus (not variola virus) which is not pathogenic but antigenic, giving cross immunity for variola.

15. L iv e a ttenu a te d ( avi ru l en t ) va cc i ne s Virulent pathogenic organisms are treated to become attenuated and avirulent but antigenic. They have lost their capacity to induce full-blown disease but retain their immunogenicity. Attenuated – live microbe (usually virus) which has a vital function inactivated by heat, chemicals or genetic manipulation e.g. Rabies virus vaccine, MMR (Bacillus (Measles, Mumps and Rubella), BCG Calmette Guerin vaccine for M. tuberculosis Risk it could revert back to infectious agent will stimulate bo t h c e ll m ediated and mediated immune response an t i b ody

16. I n a ct iva te d (k ill ed ) va cc i ne s Organisms are killed or inactivated by heat or chemicals but remain antigenic. They are usually safe but less effective than live attenuated vaccines. The only absolute contraindication to their administration is a severe local or general reaction to a previous dose

17. T oxoi d s They are prepared by detoxifying the exotoxins of some bacteria rendering them antigenic but not pathogenic. Adjuvant (e.g. alum precipitation) is used to increase the potency of vaccine. The antibodies produces in the body as a consequence of toxoid administration neutralize the toxic moiety produced during infection rather than act upon the organism itself. In general toxoids are highly efficacious and safe immunizing agents.

18. P o l ysacchar i d e an d po l ypep t i d e vacc i ne s They are prepared from extracted cellular fractions e.g. meningococcal vaccine from the polysaccharide antigen of the cell wall, the pneumococcal vaccine from the polysaccharide contained in the capsule of the organism, and hepatitis B polypeptide vaccine . Their efficacy and safety appear to be high.

19. Surface antigen (recombinant) vaccines It is p r epared b y clo n i n g HBsAg gene i n y east c e lls where it is expressed. HBsAg produced is then used for vaccine preparations . Their efficacy and safety also appear to be high .

20. TYPE S O F V ACC I NE S Live v a c cines Live A ttenuated vaccines Killed I n a c ti v at e d vaccines Toxoids Cellular fraction v acc in e s R e combi n an t vaccines Small pox variola vacc i ne BCG T y p h o i d oral Plague Oral polio Y e l l o w fever Measles Mumps Typhoid Cholera Pertussis Plague Rabies Salk polio Intra- musc u l a r influenza Diphtheria Tetanus Me n i n g o cocc a l polysaccharide vaccine P n e u moc o ccal polysaccharide vaccine Hepatitis B polypeptide vaccine Hepatitis B vaccine Rubella Intranasal Japanise e n ce p h a l i tis Influenza Typhus

21. R out e s o f a d m ini s t ra ti o n Deep subcutaneous or intramuscular route (most vaccines) Oral route ( oral BCG vaccine) Intradermal route (BCG vaccine) Scarification (small pox vaccine) Intranasal route (live attenuated influenza vaccine)

22. Sc h em e o f i mm uni z a t io n Primary vaccination One dose vaccines (BCG, variola, measles, mumps, rubella, yellow fever) Multiple dose vaccines (polio, DPT (diphtheria, pertussis, tetanus toxoids), hepatitis B) Booster vaccination To maintain immunity level after it declines after some time has elapsed (DT, MMR).