Viral pandemics Influenza and Coronaviruses Flashcards
What are three requirements for a virus to become a pandemic?
A pandemic virus will have novel antigenicity.
A pandemic virus will replicate efficiently in human cells.
A pandemic virus will transmit efficiently between people.
What is the natural reservoir of influenza A viruses?
A. Pigs
B. Chickens
C. Ducks
D. Tigers
C. Ducks
Which protein in human cells can support influenza replication?
ANP32 proteins are essential host cofactors that support influenza polymerase activity.
How can influenza polymerase utilise shorter mammalian ANP32?
Influenza polymerase can adapt to utilize shorter mammalian ANP32 homologues by mutation in PB2 subunit.
Polymerase adaptation to mammals can be achieved by a single amino acid change in PB2 E627K.
What needs to change in order for virus to successfully infiltrate humans?
Incoming virus needs to penetrate mucus and infect epithelial cells.
What contributes to incompatibility of avian-origin influenza virus with human respiratory tract?
Low acidic pH of URT followed by neutral pH of LRT
Why is influenza A currently incompatible with human-human transmission?
Avian influenza HA must adapt for transmission in humans by acquiring affinity for human receptors.
Influenza entry is pH dependent and HA protein is pH sensitive.
Are antiviral medications for influenza used together or separately?
Antiviral medications for influenza are NOT licensed to be used together (like HAART).
What are examples of neuraminidase inhibitors?
Oseltamivir
Zanamivir
What do new influenza antivirals target?
Polymerase acidic protein endonucleases.
What is an example of a polymerase acidic protein endonuclease inhibitor?
Baloxavir
The influenza vaccine given to those at greater risk of complications from flu in the UK is:
A. A live attenuated virus.
B. A purified fraction containing HA and NA of an inactivated virus.
C. A purified HA protein expressed in insect cells.
D. An immunoglobulin fraction from sera of immune patients.
B. A purified fraction containing HA and NA of an inactivated virus
What are the two types of influenza vaccine given in the UK?
Inactivated vaccine
Live attenuated vaccine
What are features of the inactivated influenza vaccine?
Split or subunit- HA rich
Given to those at risk
Short term strain specific immunity mediated by antibody to HA head
What are features of the live attenuated influenza vaccine?
Cold adapted virus limited to URT
Given to children
Broader more cross reactive immunity including cellular response