the influenza

Question 1

what does a flu virus look like?

Answer 1

eight genes inside, spikes on outer surface

Question 2

what are the parts of the virus and the human cell that binds together to trigger an immune response?

Answer 2

2 proteins on the virus’ surface- hemagglutinin (H) and neuraminidase (N)
recognized by antibodies in the immune system

Question 3

what processes does the flu virus use to change form?

“antigenic drift”

Answer 3

H proteins come in 15 varieties; N proteins come in 9 varieties– not every combination works

Question 4

what processes does the flu virus use to change form?

“reassortment”

Answer 4

mixing of genes from different flu strains; this can cause a shift in surface proteins, producing new strains of H and N numbers

Question 5

what happens after a shift or reassortment?

Answer 5

the human immune system cannot fight it as they have no antibodies to the new strain

Question 6

what part of the human anatomy does the flu virus most often attack?

Answer 6

the respiratory tract

Question 7

what are the steps involved in producing a flu vaccine?

Answer 7

surveillance
strain selection
manufacturing and production
purification and testing
filling and packaging
shipping
vaccination

Question 8

surveillance

what must be identified before production can begin each year?

Answer 8

influenza vaccine protects against three prominent virus strains (the three must be identified)

Question 9

surveillance

what is key to predicting which three strains will circulate each influenza season?

Answer 9

ongoing global surveillance

Question 10

strain selection

what do world health officials do?

Answer 10

analyze and identify the dominant circulating strains

Question 11

strain selection

why are the strains submitted to the Food and Drug Administration (FDA)?

Answer 11

to recommend which three to include

Question 12

strain selection

what does the FDA distribute?

Answer 12

seed viruses to manufacturers to begin the production process

Question 13

strain selection

what do manufacturers’ scientists predict?

Answer 13

the circulating strains for the coming season and begin preparing vaccine at risk before final FDA selection

Question 14

manufacturing and production

how are vaccines made?

Answer 14

each virus strain is produced separately and later combined to make one vaccine

Question 15

manufacturing and production

how are chicken eggs used in this process?

Answer 15

millions of specially prepared chicken eggs are used to produce the vaccine. for seven months, fertilized eggs are delivered to the manufacturer. each egg is cleaned with a disinfectant spray and injected with one strain.

Question 16

manufacturing and production

how do we collect the virus?

Answer 16

the eggs are incubated for several days to allow the virus to multiply. after incubation the virus loaded fluid is harvested

Question 17

purification and testing

how do they ensure that the virus is inactive?

Answer 17

the virus fluid undergoes multiple purification steps and a special chemical treatment

Question 18

purification and testing

how do they split the virus?

Answer 18

by chemically disrupting the whole virus

Question 19

purification and testing

what viral fragments are combined?

Answer 19

viral fragments from all three strains are collected from different batches, and combined upon completion of quality control tests

Question 20

purification and testing

why do manufacturers and the FDA test the vaccine concentrate?

Answer 20

to determine amount and yield of the virus to ensure concentrate is adequate for immunization

Question 21

filling and packaging

when is the vaccine released for distribution?

Answer 21

upon FDA approval and licensing, in time for immunization

Question 22

filling and packaging
after manufacturers begin filling the doses into vials and syringes, which are then sealed and carefully inspected, labels are applied. what do the labels show?

Answer 22

the vaccine batch, lot numbers, and expiration date

Question 23

filling and packaging

what must happen before manufacturers can ship?

Answer 23

each lot must be specifically “released” by the FDA

Question 24

shipping

when do vaccine shipments typically begin?

Answer 24

in August/September and continue into November

Question 25

shipping

why are partial shipments sent early into the season to all customers?

Answer 25

to ensure broad access for high-risk patients

Question 26

shipping
when would additional doses may be released and distributed into December and beyond to support late season immunization?

Answer 26

depending on viral yields and virus activity

Question 27

vaccination

who is immunized?

Answer 27

particular high-risk populations

other persons who wish to reduce their risk for influenza

Question 28

vaccination

when does immunization generally begin?

Answer 28

in October or as soon as vaccine becomes available and continues through the influenza season which typically ends in March

Question 29

vaccination

when does immunity develop?

Answer 29

approximately two weeks following vaccinations

Question 30

when does surveillance occur?

Answer 30

year round

Question 31

when does strain selection occur?

Answer 31

January-March

Question 32

when does manufacturing and production occur?

Answer 32

January-July

Question 33

when does purification and testing occur?

Answer 33

June-October

Question 34

when does filling and packaging occur?

Answer 34

July-December

Question 35

when does shipping occur?

Answer 35

August-November, beyond as needed

Question 36

when does vaccination occur?

Answer 36

October and beyond

Question 37

what processes does the flu virus use to change form?

“jumping”

Answer 37

viruses that infect different species combine viral genes during replication process