Influenza Pandemics Flashcards
Which flu occurred in 1918?
Spanish flu
Spanish flu subtype?
H1N1
Which flu occurred in 1957?
Asian flu
Asian flu subtype?
H2N2
Which flu occurred in 1968?
Hong Kong flu
Hong Kong flus subtype?
H3N2
Which flu threat occurred in 1997?
Avian bird flu threat H5N1
Which flu occurred in 2009?
Swine flu
Swine flu subtype?
H1N1
Which flu threat occurred in 2012?
Avian bird flu threat H7N9
Why is H7N9 so concerning?
Dual receptor binding affinity
In February 2017 noticed HPAI - was causing chickens do die
PB2 627K mutation has been observed in the virus infecting humans
Where did Spanish flu start?
Kansas
Why was Spanish flu so severe?
Caused cytokine degranulation
Caused a cytokine storm to occur
Spanish flu killed an estimated?
20 to 50 million individuals
Why was it thought that the Hong Kong flu was not so severe?
Was H3N2
Has the same neuraminidase as the flu virus from the 1957 Asian flu threat: H2N2
May have had some cross-reactive immunity due to the shared neuraminidase
The Gain of Function research looked at which influenza in particular?
H5N1
Gain of Function research aimed to?
Establish which mutations would be required to make H5N1 transmissible between humans and to evaluate the likelihood of this occurring in nature
Gain of function research allowed the spread of H5N1 between?
Ferrets
What are the benefits of gain of function research?
- Allows us to establish what mutations are required for transmission between humans
- Allows us to evaluate which influenza viruses are the most likely to cause pandemics
- Allows governments to make informed decisions about which vaccines they would like to stockpile
- Has given us an insight into what is needed for bird flu to spread in humans e.g. PB2 mutation
- Aids in drug development
What are the disadvantages of gain of function research?
- Threat to biosafety and biosecurity
- Could be used in bioterrorism if we make the information readily available to all
- There is a threat of release, accidental release may occur
What are the alternatives to gain of function research?
IRAT
Influenza Risk Analysis Tool
Created by the WHO and industry experts
States that the virus most likely to cause the next pandemic is H7N9
Swine flu has now become?
Seasonal flu
Where did swine flu first appear?
First appeared in Mexico
Swine flu originated in?
Pigs
What is H3N2v?
Influenza variant virus
H3N2v originated in?
Pigs
How can H3N2v spread to humans?
When humans are in close proximity to pigs e.g. at agricultural fairs
Why might it be worth creating a vaccine/stockpiling drugs against H3N2v?
Does not seem to be changing
Antigenically stable
Why is H3N2v not evolving and developing mutations?
Pigs do not live long enough (slaughter) to become re-infected. This means there is no selection pressure from the immune system to cause the virus to drift.
H3N2v can be described as evolutionarily?
Static
When did H7N9 cause its first human death?
2013
What happened to h7N9 in February 2017?
Was seen to kill chickens
Became HPAI
HPAI?
Highly pathogenic avian influenza
H7N9 human mortality rate?
Extremely high
40%
Why is H7N9 so concerning?
Shows dual receptor binding ability
Has been shown to undergo the PB2 627K mutation in infected humans
High mortality rate in humans: 40%
What was the Chinese government’s response to H7N9?
Began vaccinating chickens against H7N9 in 2017
What is a cheap cost-effective way of identifying if a person is infected with influenza?
Influenza hemagglutinin assay
What is a way of identifying the subtype someone is infected with?
Agglutination inhibition
If you are able to prevent agglutination by using antibodies against a specific subtype of influenza hemagglutinin you can confirm the hemagglutinin subtype an individual is infected with
