2009 H1N1

Question 1

What facilitated the rapid transmittance of H1N1 (2009) in pigs?

Answer 1

crowded conditions + long distant transport –> developement and spread of new strain

Question 2

Give the old and new definitions of Phase 5 and 6 pandemics, as defined by WHO

Answer 2

Phase 5

• old: evidence of significant human –> human transmission
• new: the same identified virus has causes sustained community-level outbreaks in at least two countries in one WHO region

Phase 6

• old: efficient and sustained human –> human transmission
• new: phase 5 + sustained community-level out break in at least one other country in a different WHO region

Question 3

what is the mechanims of infection of H1N1?

Answer 3

direct close contact: coughing, sneezing, or contract with contaminated droplets through fomites; not airborne

Question 4

What are some conditions of pH1N1 environmental survival?

Answer 4

• 0-4C: soruvives for many weeks and still viable
• lose infectivity aroun -20C
• more susceptible to acidic pH

overall: pretty resistant

Question 5

What is the differences between influenza A vs B and C?

Answer 5

A, B, and C are distinguished by Ag differences in two of their internal proteins

type A is typlically found in warm-blooded animals (zoonotic potential); whereas B and C are primary human pathogens

type A strains are identified of hemagglutinin (HA) and neuraminidase (NA)

Question 6

What is tissue tropism?

Answer 6

cells and tissues of a host which support growth of a particular virus

Question 7

Which antibodies are secreted in the upper vs lower respiratory tract? Which one is a major factor in resistence to natural infection?

Answer 7

upper = sIgA (major)
lower = IgG

Question 8

Why were pigs the vessel for the tripple reassortment of Influenza A?

Answer 8

human influenza HA binds to a2-6 SA
avian influenza HA binds to a2-3 SA

pig respiraotry eptithelial cells express both

Question 9

What does is mean for something to be antigenic vs immunogenic?

Answer 9

antigenic: pathogen molecule that interacts with host Abs or ICs

immunogenic: induces an innate AND adaptive immune response

Question 10

what aspects of immunity have to evoked to provide a protective function for a vax?

Answer 10

• appropriate site
• of relevant nature (Ab, Th1, Th2, Tc)
• of adequate duration

Question 11

Name two adjuvants and state what type of immune response they induce. What do adjuvants in general also do?

Answer 11

• Alum –> favours human Ab responses (Th2)
• Fruend’s complete adjuvant –> Th1

in general

• activate acute local inflammation resposnes (e.g. cyotkines) and key players like DCs
• mainitain high local [Ag]

Question 12

Whats in the 2023 flu vaccine?

Answer 12

• influenza A and B
• pH1N1