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http://highered.mcgrawhill.com/sites/0072495855/student_ view0/chapter24/animation__the_i mmune_response.html Acquired Immunity Naturally acquired Active •Antigens enter body naturally •Antibodies & specialised lymphocytes produced Passive Artificially acquired Active •Antibodies pass from mother to foetus •Antigens are introduced in vaccines •Infant does not produce any antibodies of its own •Antibodies & specialised lymphocytes produced Passive •Antibodies are introduced in an immune serum •Body does not produce any antibodies of its own http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it =swf::525::530::/sites/dl/free/00724 64631/291136/constructing_vaccine s.swf::constructing_vaccines.swf Whole-agent vaccine Contains whole, non-virulent micro-organisms Inactivated (killed) • Inactivated with ? • Rabies, most influenza vaccines Live attenuated (weakened) • Made from live virus • Altered to be less harmful • Oral polio, MMR and BCG, yellow fever and one form of typhoid vaccine Subunit vaccine Parts of pathogen that can serve as ? • Toxoid – Made from the toxin (poison) – Inactivated by heat/chemicals – Diphtheria, tetanus • Recombinant – gene for antigen inserted into? – Hep B • Conjugated • Acellular , and ? Herd Immunity • Members of a community who are not immune to a disease are still protected, provided sufficient numbers of people in that community are immune • Little opportunity to spread and find a non-immune person • Only applies to diseases that are caught from other people http://www.who.int/features/fact files/immunization/facts/en/inde x8.html Flu • • • • • • • Influenza virus 3 types: ? Vaccine from hens eggs 70-80% effective Antigenic drift – Antigenic shift – WHO – monitors spread of influenza viruses worldwide = Use vaccine with current common antigens Common Cold • Caused by a rhinovirus • ? strains! • Therefore… Malaria • • • • • Caused by a protocist Eukaryotes have + + + genes Lots of antigens on cell surface ? life stages – each with specific antigens Therefore… • Only work if immune system gives an effective, immediate response ( hours) European Immunisation Week 2008 • Write a newspaper article reporting on the benefits of childhood immunisation. • You must include: – A detailed explanation on the principle of vaccination – Diseases that can be prevented by vaccination – Statistics (e.g. decrease in number of cases) – A quote from a parent or a doctor/nurse – Problems with vaccines (see pg229) – A quote from an epidemiologist concerned with world health – Use at least ten words from the list on the board Word List Antigen Antibodies/antibody Artificial (active) immunity Epidemic Injection Infectious Immunity Immune response Herd immunity Poor response Vaccine/vaccination Memory B cells Polio Diptheria MMR Tetanus Rubella Measles HPV Tuberculosis http://www.mmrthefacts.nhs.uk/ worldmap/map6.php MMR • Write a newspaper article reporting on the MMR scare. • You must include: – A detailed explanation on the principle of vaccination – Two problems with vaccines in general (see pg229) – Arguments for and against the MMR vaccination – Voice a major concern from a parent – A counter-argument from a doctor/nurse and an epidemiologist concerned with world health – Use at least ten words from the list on the board Allergies • Immune response to harmless substances • Allergens (antigenic) e.g. house dust, animal skin, pollen • Asthma, hayfever and eczema • Immune response: • B cells produce IgE antibodies • Coat surfaces of mast cells • Body sensitised • Second ‘exposure’ – allergen binds to IgE on mast cells • Histamine released, blood vessels widen, become leaky • Fluid and white blood cells leave capillaries • Hot, red, inflammed Hayfever • Seasonal allergic rhinitis, • Allergic reaction to pollen • Irritation and inflammation to the lining of the eyes, nose and throat. • Mostly grass pollen, some tree pollen and/or weed pollen • Symptoms include: – – – – – – – watery, itchy and red eyes, frequent sneezing, itchiness in nose, ear and throat, a dripping or stuffy nose, head congestion, chest wheeziness lethargy. Asthma • • • • • • • • • Allergic reaction to: Animal proteins Pollens Mould spores Smoking Weather Viral infections Emotions Hormones Asthma attack: Anagrams Quick Questions 1. Define the terms antigen and antibody. 2. Why does the secondary immune response differ from the primary? 3. What is an allergy? 4. Describe four ways in which antibodies work to protect the body against pathogens Q4 Answers Attach to flagella: less active/easier for phagocytosis Agglutination: reduces spread through body Make holes in cell walls: lysis of bacteria Combine with toxins/viruses: prevent entering/damaging cells Combine with toxins: neutralise bacteria