GM vaccine Flashcards
how many people suffer from diseases which could be preventable via vaccination
2 billion
what does current research focus on
DNA plasmids vectors transgenic plants viruses non pathogenic organisms
antibiotics have no
immunological memory
antibiotics increase the risk of
resistant strains of pathogen
antibiotics do not work against
viruses
how can we prevent the disease
vaccination
define vaccination
exposing a person to material that is antigen but not pathogenic
currently have vaccinations for many diseases such as
TB - BCG chicken pox measles diphtheria yellow fever polio mumps
what was the mortality rate of small pox
30%
who performed first experimental vaccination
edward jenner
when was small pox virus deemed irradiated
1977
how does a vaccine wotk
stimulates immune system via antibodies
creates memory cells so antibodies are quicker next time
what is the 2 pronged attack
helper T and B lymphocyte
what type of a response is B lymphocyte
humoral - attack outside cells
what do killer T cells do
attack infected cells and pathogen inside
when does proliferation of B cells occur
primary response when first infected
how long is required for the B cells to generate the maximum effector cell response
10-17 days
if body is exposed to an antigen again later how long does it take for B cells to generate the maximum effector response
2-7 days
what is secondary exposure known as
secondary response
what makes a vaccine safe
doesn’t cause illness or death
what makes a vaccine protective
protects against illness resulting from exposure from pathogen
how long should the protection from a vaccine last
at least few years
what are practical considerations for vaccines
low cost
biologically stable
ease of administration
few side effects
what does polo vaccine need and why
neutralising antibody as polio infects neutrons which cannot be replaced
name the 2 types of vaccine
killed inactivated and live attenuated
describe killed vaccie
don’t develop disease
name killed vaccine
hep A
polio
whooping cough
are killed vaccines safer than live ones
yes
when microbes are killed, what must it not alter
the antigens responsible for stimulating immunity
which response do killed vaccines create
humoral - don’t usually get T killer involved
what are the problems with killer vaccines
only produce humeral
not effective against pathogens that infiltrate cells
need booster as effect wares off
describe live attenuated vaccine
a process which lessens the virulence of the microbe
what is a live attenuated vaccine used for
viruses, such as measles, mumps, rubella
how does the live attenuated vaccine work
multiply like normal organism,
activated all phases of immune system
raises immune response for all protective antigens
quick immunity
advantage of live attenuated
quick immunity
spread to contact of vaccinee even if they haven’t connected (heard immunity)
no need for booster
disadvantages of live vaccine
mutation - reversion to virulence
spread to contacts who haven’t given concent
problem in immunodeficiency disease and pregnancy
what is a recombinent live attenuated vaccine
modification of pathogen - e.g.. delete virulence genes and leave others which gives immune response
give an advantage of recombinant live attenuated vaccine
can add other immunity inducing genes from other diseases to produce polyvalent vaccine
what is a subunit vaccine
use antigenic fragments which best stimulate immune response
contain specific subunit of protein
disadvantages of subunit vaccine
less effective then whole agent vaccines - adjuvants usually needed
costly
always require boosters
advantages of subunit vaccine
single antigen
safer as cannot reproduce
which specific protein subunit is used in subunit vaccines
usually protein coats or modified toxin
what is a DNA vaccine
DNA sequence used as the vaccine
how does DNA vaccine work
put DNA sequence for antigenic protein pathogen into cells and is translated to form antigenic protein
this is foreign to cells so immune response triggered
advantages of DNA vaccine
uses only DNA from infectious organism
avoid risk of using actual organism
provide both humeral and cell mediated immunity
refrigeration is not required
disadvantages of DNA vaccine
insertional mutagenesis chromosome instability turn on oncogenes turn off tutor suppression genes antibodies produced against antigen can cause autoimmune disease
DNA vaccines are being developed against —
rabies
malaria
aids
when were edible vaccines first tested on humans
1997 - antidiahroal potato
advantages of edible vaccine
direct contact with mucosal lining
good for third world
injections dont stimulate immunity very well
problems with edible vaccine
amount made by plant is usually very low - need to make sure its enough to stimulate immune response
plants grow poorly when producing loads of vaccine
what is the best edible thing for the vaccine
potato
- stored long period without refrigeration
some countries eaten raw
and heat doesn’t denature protein
disadvantage of using potato
need to be cooked usually might denature
other good examples of edible vaccine things
banana
tomato
