III - vaccines

Question 1

what is measles and what is it caused by

Answer 1

respiratory system infection
caused by a paramyxovirus

Question 2

what is herd immunity

Answer 2

immunity developed by a group of vaccinated individuals

Question 3

what is amantadine and how does it effect influenza virus

Answer 3

antiviral
blocks M2 ion channels on the envelope of the virus
prevents viral genetic material from exiting the virus

Question 4

what are zanamivir and oseltamivir and how do they perform their role

Answer 4

they are neuraminidase inhibitors
inhibiting the neuraminidase enzyme prevents budding and therefore the release of new virus from the host cell

Question 5

function of neuraminidase

Answer 5

cleaves polysaccharides of the host cell surface

Question 6

what is hemagglutinin

Answer 6

proteins on the surface of influenza
bind to host cell surface

Question 7

what are both hemagglutinin and neuraminidase

Answer 7

the two main influenza antigens

Question 8

what are the subtypes of influenza A

Answer 8

H - hemagglutinin - types H1-H18
N - neuraminidase - types N1-N11

Question 9

what are the lineages of influenza B

Answer 9

yamagata
victoria

Question 10

what are the 2 mechanisms to generate variations in influenza

Answer 10

antigenic drift
antigenic shift

Question 11

what is antigenic drift

Answer 11

overtime the amount of point mutations that occur results in an antigen that isn’t recognised by the antibody that recognised the original

Question 12

what is antigenic shift

Answer 12

when an animal and human influenza infect the same cell
the ssRNA gets rearranged between them
leads to completely different antigens
unrecognised by antibodies

Question 13

what influenza strain is the swine flu and what type of vaccines have been developed for it

Answer 13

H1N1
inactivated or live attenuated vaccines

Question 14

what are antigenic drift/shift responsible for

Answer 14

drift - seasonal flu
shift - pandemics

Question 15

what are the incubation periods of influenza and polio virus

Answer 15

influenza - 1-2 days
polio - 3 days

Question 16

an effective influenza vaccine must be what

Answer 16

able to maintain high levels of serum antibodies because the disease is already underway before memory B-cells can be activated

Question 17

what are the advantages/disadvantages of live attenuated vaccines

Answer 17

advantages - stronger immune response
usually lifelong immunity
disadvantages - requires refrigerated storage
may mutate to pathogenic form

Question 18

what are the advantages/disadvantages of dead/inactivated vaccines

Answer 18

advantages - safer
refrigeration not required
disadvantages - weaker immune response
boosters usually required

Question 19

list the vaccine types

Answer 19

live attenuated
dead/inactivated
conjugate
toxoid
subunit

Question 20

what are some live attenuated vaccines

Answer 20

polio
MMR
TB

Question 21

how is attenuation achieved and explain them

Answer 21

natural attenuation - inoculation (Jenner)
serial passage - select mutants with reduced toxicity

Question 22

what is chemical mutagenesis

Answer 22

it is a method of attenuating a virus
virus is extracted from a patient and cultured in human cells
they are then used to infect monkey cells
they pick up mutations that allow them to better effect monkey cells
lose ability to grown in human cells

Question 23

features of the sabin vaccine

Answer 23

given orally
induces IgA, IgG and IgM responses
consists of 3 attenuated serotypes of polio
gives immunity for all 3 strains
requires 2 extra boosters

Question 24

what is the wild-type progenitor strain genome of sabin made up of and how different is the sabin vaccine

Answer 24

7249 nucleotides
the sabin vaccine is different by only 9 nucleotides

Question 25

how does recombinant DNA allow for safer live attenuated vaccine production

Answer 25

able to isolate the virulence gene either delete or mutate it reversion to virulent form is basically impossible

Question 26

what key genes of malaria are deleted to produce its vaccine and what is the outcome

Answer 26

deletion of p52 and p36 prevents productive liver infection

Question 27

what are examples of deactivated vaccines

Answer 27

pertussis cholera typhoid polio influenza zika

Question 28

how is a virus inactivated

Answer 28

application of heat or chemical - formaldehyde or alkylating agents nucleic acids are destroyed antigens remain intact

Question 29

why do inactivated vaccines only produce a humoral response

Answer 29

because pathogen does not replicate

Question 30

what is the main concept of a subunit vaccine

Answer 30

introduce only a subunit of the pathogen to host (only gp120/41)

Question 31

what are the 3 main subunits isolated to form a subunit vaccine

Answer 31

toxoids capsular polysaccharides recombinant protein antigens

Question 32

what are examples of subunit vaccines

Answer 32

hepatitis B streptococcus pneumonia diphtheria tetanus

Question 33

what is the concept of a toxoid vaccine

Answer 33

exotoxin is purified and inactivated via formaldehyde

Question 34

what are examples of toxoid vaccines

Answer 34

diphtheria tetanus

Question 35

what can increase the abilities of macrophages/neutrophils to phagocytose bacteria with the anti-phagocytic properties of their hydrophilic polysaccharide capsule

Answer 35

coating the hydrophilic capsule with complements and antibodies

Question 36

what is an adjuvant

Answer 36

any material that can increase the humoral and cellular immune response to an antigen

Question 37

how do adjuvants increase the immune response of inactivated/subunit vaccines

Answer 37

act directly on macrophages/neutrophils and dendritic cells leads to adaptive immune response

Question 38

what is the process by which adjuvants stimulate the innate immune system

Answer 38

attract APC's stimulate pattern recognition receptors (TLR) induces inflammasome activation leads to antigen presentation on MHC molecules

Question 39

what can be used as an adjuvant

Answer 39

aluminium salts virosomes MPL MF59

Question 40

what are the potential side-effects of adjuvant use

Answer 40

redness, swelling and pain at injection site systemic reactions - fever, chills and body ache

Question 41

how do conjugate vaccines solve the problem of a poor immunogenic response

Answer 41

fuse a highly immunogenic protein to the weak vaccine

Question 42

give an example of a conjugate vaccine

Answer 42

haemophilus influenza type B (Hib) vaccine

Question 43

what does Hib cause

Answer 43

bacterial meningitis

Question 44

what does the conjugate vaccine of Hib consist of

Answer 44

the type b capsular polysaccharide fused to tetanus toxoid - highly immunogenic

Question 45

what do conjugate vaccines activate and not

Answer 45

activate - T helper and memory B cells does not activate - memory T cells