Influenza vaccines

Question 1

influenza envelope proteins

Answer 1

haemagglutinin (important for antigen binding), neuraminidase

Question 2

importance of neuraminidase

Answer 2

not the main antibody binding target, but can be a target for cellular immunitym and might kinda ilicit an antibody response?

Question 3

antigenic shift

Answer 3

‘process by which two or more different strains of a virus, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains’

Question 4

2 main types of flu vaccine

Answer 4

inactivated flu vaccine (can be tri- or quadrivalent)
live attenuated vaccine (LAIV), quadrivalent

Question 5

where on haemogglutinin do mutations tend to occur

Answer 5

at the head region

Question 6

examples of universal vaccine approaches

Answer 6

HA-directed approaches, such as targeting the stalk, mosaic HA vaccines which target bits which are the least likely to change

NA-directed approaches

targeting internal proteins

Question 7

what might limit diversity

Answer 7

some epitopes need to be conserved for functionality reasons

short-lived and non-specific cross-immunity- potentially less of a selection pressure?

Question 8

antigenic thrift theory

Answer 8

idea that there actually is long-term cross-protective immunity against influenza, kinda opposes antigenic drift ideas

Question 9

evidence of antigenic thrift

Answer 9

swine flu epidemic being due to loss of herd immunity, rather than epitope changes (they were v similar)- people who were around in 1918 did very well against swine flu, suggests not everything is about changing epitopes