Immunity and Vaccines

Question 1

Vaccines

Answer 1

always contain antigens that cause your body to produce memory cells against pathogen WITHOUT SYMPTOMS/PATHOGENS CAUSING DISEASE
antigens either free/attached to dead or weakened pathogen
May be injected or taken orally
Booster vaccines given later on to ensure memory cells are produced

Question 2

Antigenic Variation

Answer 2

A change on a particular pathogen due to changes in pathogen genes
upon second reinfection, memory cells do not recognise different antigens so primary response has to start again
Primary response takes time which is why you feel ill again
Difficult to develop vaccines for some pathogens because of this i.e. HIV and Influenza

Question 3

Active Immunity

Answer 3

when immune system makes its own antibodies after antigen exposure
Natural = immunity after catching disease
Artificial = immunity post vaccination
requires antigen exposure
takes a while for protection to develop
Mem. cells produced
long term protection

Question 4

Passive Immunity

Answer 4

when antibodies given made by different organism
Natural = i.e. baby receives antibodies through milk/placenta
Artificial = emergency injections for disease i.e. tetanus
No antigen exposure required
Protection is immediate
Mem. cells not produced
short term protection ( AB broken down)

Question 5

Issues with oral?

Answer 5

oral molecules may be broken down by enzymes/too big to be absorbed into the blood

Question 6

Ethical issues

Answer 6

All tested on animals
some use animal based substances in production
human volunteers put themselves at unnecessary risk if they think they’re protected (i.e. unprotected sex with HIV vaccine)
unfair that those who don’t take because of side effects are protected by herd immunity
in epidemic, who would be the first to receive it?