Vaccines and Immunity Flashcards
1
Q
Which immune mediators are transferred via mother’s milk?
A
- TGF-β in humans, cattle, possibly other species
- lactoferrin in humans, cows - part of innate immune system (anti-microbial)
2
Q
What is increased and decreased in breast-fed children serum?
A
- increased regulatory TGF-β
- decreased regulatory TGF-α
3
Q
What is breast feeding associated with?
A
- lower hypersensitivities - not all and not absence
- reduced GI, respiratory infections in infants
4
Q
What are some examples of anti-sera/passive immunity?
A
- tetanus and other toxoid-releasing pathogens
- hepatitis A and B
- immunodeficient individuals
5
Q
How does passive immunity end?
A
end eventually due to catabolism of antibodies
6
Q
Describe the Janaka et al 2021 case study
A
- donor anti-spike immunity related to recipient recovery and can predict efficacy of convalescent plasma units
- of those with severe covid, only 65% created plasma reached protective levels
- less hospital death with anti-spike antibody titre, more with anti-nucleocapsid
7
Q
What needs to balanced in vaccines and how is it achieved?
A
- need to mimic natural infection
- activate innate immune system -> adaptive immune system
- one way to help is mixing the vaccine with an adjuvant
8
Q
Describe adjuvants
A
- any substance that, when given with an antigen, enhances the immune response to that antigen
- activates the innate immune response
9
Q
Describe Alum
A
- main adjuvant method is slow release of antigen
- also can lead to damage (DAMPs) activating DCs and macrophages
- aggregates which makes easily phagocytosed
- mainly Th2 activation - not cell mediated
10
Q
Describe immunostimulatory adjuvants
A
- dsRNA, CpG, saponins
- called QuilA - stimulates cytokine production
- Th1 stimulatory - used in horse, cat, dog, cattle vaccines
- e.g., FeLV recombinant vaccine
11
Q
Describe Covid-19 vaccines
A
- no reported adjuvants
- astra zeneca oxford - actual virus - can activate innate immune response
- moderna & pfizer/biotech - lipid nanoparticle/mRNA
12
Q
What are the 3 types of vaccine?
A
- live attenuated
- killed
- subunit
13
Q
Describe the live attenuated vaccine
A
- still viable pathogen but reduced pathogenicity
- can cause infection but not disease
- attenuated by deliberate passage
14
Q
Describe the effects of live attenuated vaccines on the general immune response
A
- strong, appropriate response
- cellular immunity
- humoral immunity - including secretory IgA depending on pathogen
- long-lasting memory
15
Q
What are the advantages of live attenuated vaccines?
A
- multiple antigens
- single immunisations
- easy to produce without a genome of pathogen
- may not require an adjuvant
