lecture 12) vaccines and vaccinology

Question 1

what is the only infection to have been eradicated worldwide due to vaccination?

Answer 1

smallpox

Question 2

why does the oral vaccination for polio give a continued risk for the virus circulating in the population?

Answer 2

IPV induces low levels of immunity in the intestine
when immunised with this vaccine the inactivated virus can multiply in the intestines
it is excreted in faeces therefore will continue to be in circulation

Question 3

what disease can arise years after the measles infection?

Answer 3

subacute sclerosing panencephalitis (SSPE)

rare and chronic inflammation of the brain due to persistent infection of measles

Question 4

give 2 potential outcomes of being naturally infected with a pathogen

Answer 4

succumb to disease/potentially die

make recovery due to natural immunity and be against re-infection

Question 5

will you be protected against re-infection of all diseases if you have had the infection once?

Answer 5

not true for all disease
some dont offer immunity to re-infection
these diseases are the hardest to design a vaccine for

Question 6

give 3 characteristics of vaccines

Answer 6

mimic natural disease
trick body into thinking it has been infected
only work if the body can generate a protective response

Question 7

what are the 2 types of protective responses the body has when infected?

Answer 7

antibodies

cellular immunity

Question 8

what type of cells are antibodies made from?

Answer 8

B cells

Question 9

what do CD4+T cells do?

Answer 9

orchestrate immune response

Question 10

what do CD8+T cells do?

Answer 10

kill infected cells

Question 11

name the 4 main types of vaccines

Answer 11

live
killed
sub-unit
naked DNA

Question 12

describe live vaccines

Answer 12

living microbes that cannot cause disease due to some genetic disruption but can still infect
best mimic
most traditional approach

Question 13

describe killed vaccines

Answer 13

killed microbes by heating or exposure to chemicals
chemicals not favoured as they are introduced into body
traditional approach

Question 14

describe sub-unit vaccines

Answer 14

fragments of microorganisms eg proteins

only need some components of microorganism to cause infection

Question 15

describe naked DNA fragments

Answer 15

piece of DNA of a microbe

makes proteins after injection

Question 16

what is the disadvantage of only having 1 mutation being the difference between a disease causing microorganism and an attentuated microorganism for a vaccine?

Answer 16

more potential for reversion of that mutation

greater likelihood of the vaccine cause infection

Question 17

what cause the outbreak of polio in Hispaniola in 1999?

Answer 17

reversion of the polio vaccine

Question 18

what is the most ideal immune response for subunit vaccines?

Answer 18

antibody mediated response

Question 19

what are the advantages of having pure components in subunit vaccines?

Answer 19

more potent
fewer side effects
good responses

Question 20

what 2 components are combined to make a vaccine against plague?

Answer 20

F1

V antigen

Question 21

what is F1 in plague?

Answer 21

peptide that assembles on the cell surface to form a capsule

Question 22

what is the V antigen in plague?

Answer 22

peptide on cell surface that forms the tip to the T3SS
T3SS essential for bacterium to cause disease
acts as needle that punches host cell to inject it

Question 23

describe the concept of having vaccines in plants?

Answer 23

grow a crop of vaccine
transfer genes into plants that will produce proteins
humans eat the plants - become immune

Question 24

what are the pros of having vaccines in plants?

Answer 24

easy to produce
focused immune response
nonreactive
highly protective

Question 25

what are the cons of having vaccines in plants?

Answer 25

no CD8 cells therefore wont be effective for diseases that require more than just antibodies eg TB

Question 26

what are some of the main problems of naked DNA vaccines

Answer 26

DNA could mutate
works well in mice but mostly failed in humans
rely on the DNA naturally decaying but could be integrated into the host’s genome

Question 27

what 4 areas are vaccines hoping to help in the future?

Answer 27

infectious diseases (public health/AB resistance, bioterrorism, animal health vaccines)
cancer
degenerative diseases eg alzheimers
addition eg heroin addiction