Lesson 5 (Part 2) Flashcards
Antigenic drift
Occurs when the proteins are altered by genetic mutation and selection
- can store and express viruses at a later time
What can viruses accumulate? What does it allow?
- Accumulates gene mutations
2. Allows them to change antibody binding sites
Antigenic shift
Occurs when two or more different strains of a virus or when two completely different viruses share RNA leading to a new mix of surface antigens from the original strains of viruses
Where can antigens (viruses) proliferate?
Inside the cell
Where do viruses need to be in order to reproduce?
Inside the same cell at the same time
How does WHO predict where the flu will be?
They look at where it was the previous year and its patterns and where is was moving
When do seasonal epidemic pandemics occur?
Mainly in the winter
- except in the tropical regions where the “season” is year round
Who is effected by epidemics/pandemics?
Everyone
- especially health care workers
Why are health care workers more effected by epidemics/pandemics? (4)
- Commonly exposed
- Shift workers
- Effected by sleep
- which effects the immune system - Eat poorly
- dont have a ton of time
Who are more susceptible to epidemics/pandemics? (6)
- Children less than 5 years old
- The elderly
- Pregnant women
- People with chronic medical conditions
- People undergoing chemotherapy
- People with compromised immune function
Why are children under 5 years old more susceptible to disease? (2)
- Havent been exposed to much
- no imminities - Underdeveloped immune system
Why is the elderly effected by the immune system?
Slower to react
When is a slower reaction rate to a disease a good thing?
Dont get the fatal symptoms
Why are pregnant women susceptible to disease? (3)
- Blood pressure is working overtime
- Baby needs to feed also
- not as much nutrients - Lack of sleep
What is being looked at when classifying a virus?
Outside the cell
- even though the interior could be different
How many Influenza phases are there?
8
What are the Influenza phases? (5)
- Phase 1-3
- Phase 4
- Phase 5-6
- Post peak
- Post pandemic
Who is predominantly effected in phases 1-3?
Animals
- few humans are infected
What happens in phase 4?
Sustain human to human transmission
What happens in phase 5-6?
Widespread of human infection
- pandemic
What happens in the post peak phase?
Possibility of recurrent events
- but on the decline
What happens in post pandemic phase?
Disease activity at seasonal levels
- back to normal
What strains are covered in each years vaccine? (3)
- Influenza A (H1N1)
- Influenza A (H3N2)
- Influenza B (one or two strains)
What does the flu vaccine protect us against?
Protects us against flu viruses that are the same or related to the viruses in the vaccine
