Vaccinations and Allergies. 1.Active Immunity “actively” producing antibodies to fight...
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Transcript of Vaccinations and Allergies. 1.Active Immunity “actively” producing antibodies to fight...
Vaccinations and Allergies
Passive vs. Active Immunity
1. Active Immunity“actively” producing antibodies to fight infection.Ex: You have a throat infection and you are actively creating antibodies to fight
it.
2. Passive Immunity
antibodies are given to a person from the blood of another person or animal.
This immunity only lasts for a short period of time.
ex: Breastfeeding mothers pass antibodies to their children through the milk.
Vaccination
A preparation containing antigenic material:Whole live microorganismDead microorganismAttenuated (harmless) microorganismToxoid (harmless form of toxin)Preparation of harmless antigens
Vaccination: An injection of a weakened strain of an infectious microbe (pathogen) that causes the body to undergo active immunity (produce antibodies).
Why aren’t they always effective?Immunosuppressed patientsMalnutrition, particularly proteinAllergy to latex or egg
Smallpox –Variola virus
Symptoms:Red spots containing transparent fluid all over bodySpots filled with pusEyelids swell and become glued together
Smallpox
Mortality:12-30%Survivors often left blind and disfigured with scars
Smallpox
Eradication:Started by WHO 1956Aimed to rid world of smallpox by 1977Involved aggressive vaccination and surveillance policiesOver 80% of populations at risk of disease were vaccinatedAfter any reported case, everyone in the household and 30 surrounding houses were vaccinated
Smallpox
Smallpox Last case reported in Somalia in 1977 World declared free of smallpox in 1980
Smallpox scars on 10,000BC mummy
Smallpox Why was eradication successful?Virus is stable, doesn’t mutateCheap vaccine made from harmless strain of similar virusVaccine can be used at high temperaturesEasy to identify infected peopleDoesn’t lie dormant in body
MeaslesAirborne virus9th leading cause of death worldwide
Symptoms:Rash and high fever (104⁰)
MeaslesTransmitted easily in crowdsAffects malnourished infants with vitamin A deficiencyCan cause severe brain damage, blindness, and sterilityHerd immunity of 93-95% needed to prevent transmission in a population
Allergies
When the immune system responds to harmless substances
Allergens – antigenic substances which do no real harm
Allergens include house dust, animal skin, pollen, house dust mite and its faeces
There are two types of allergic reactions.
a. Immediate – occurs within seconds and normally lasts for about 30 mins.
b. Delayed – takes longer to react and can last for a much longer time.
What happens during an allergic reaction?
During an allergic reaction antibodies cause histamines to be released from certain cells.
Histamines cause:
a. Swelling of tissues
b. Release of fluids (runny noses and eyes)
c. Muscle spasms (some cases)
Example: TB (Mantoux test)
Allergies
Histamine causes blood vessels to widen and become leaky.
Fluid and white blood cells leave capillaries.
The area of leakage becomes hot, red and inflamed
Anaphylaxis or anaphylactic shock:This is the sudden and severe allergic reaction to a substance that can cause death.
-inherited tendency to over-produce IgE (evolved to protect against round and flat worm infection)
Treatments for Allergies1. Avoidance of material – especially food.2. Epinephrine – “epi – pen”3. Antihistamines -- benadryl
Autoimmune Disease
Autoimmune diseases are diseases where the immune system begins to attack itself.
◦ Ex: ◦ Rheumatoid Arthritis – crippling disease of the joints.◦ Lupus – disease of blood and organs.◦ Multiple Sclerosis – disease of nervous system
Cause(s): mostly unknown; virus alters proteins,T cells don’t differentiate properly; a nonself may resemble a self antigen
More common in females –fetal cells transport through circulation and cause later response
Cures/Treatments: No known cures. Usually treated with drugs.