vaccines - MissFinniganBiology
Download
Report
Transcript vaccines - MissFinniganBiology
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