Influenza A Flashcards
What genome does Influenza A have?
- ss RNA
How many genome segments are present in the NC?
8, each with 1 ORF encoding virus proteins
What type of infection does it cause?
Localised and transient
What enzymes (if any) are carried with the genome?
RdRp
From what family does it come from?
Orthomyxoviridae
What proteins are present on the virus envelope?
Haemagluttinin and Neuraminidase
What shape is the NC?
Helical
What receptors does flu A bind to for single cell infection?
Sialic acid-linked glycan
Humans: 2,6 linkage (high transmission, low virulence)
2,3 linkage (low transmission, high virulence)
Avian: 2,3 linkage
Swine: Both 2,3 and 2,6
How does the virus enter a cell?
R-M endocytosis
What is its mode of transmission?
Respiratory
What Toll-Like Receptors will detect this virus?
TLR 7 (ssRNA)
Name three host species.
Humans, Pigs, Birds
What is antigenic shift?
When new strains are formed, usually through re-assortment of genome segments into a new virion from a cell infected with two different influenza strains.
What is antigenic drift?
RdRp carried in virion does not proofread giving rise to mutations. These are frequent enough that the immune system does not recognise the virus if a host is reinfected with the same virus one year after first being exposed. This is why it is important to get flu vaccinations each year.
What type of vaccine is used to protect against infection?
Inactivated vaccine.
