Vaccinology

Question 1

True or False. Vaccines are usually used as a key metric in level of development.

Answer 1

True

Question 2

True or False. Vaccines are the most cost-effective method for dealing with infectious threats to human populations,

Answer 2

True

Question 3

How is immunological memory/ vaccine response measured?

Answer 3

IgG titre

Question 4

What is immune memory?

Answer 4

It is the increased ability to proliferate of memory T/B cells post infection

Question 5

What is R in vaccinology?

Answer 5

Rate of Ab decay/Rate of Ab synthesis

Question 6

How does the Abs produced after vaccination change upon multiple doses?

Answer 6

1st dose: primarily IgM, some IgG later on
Subsequent doses: Early IgG response&raquo_space;» IgM prod.

Question 7

Responses to vaccines in a population are _____.

Answer 7

Heterogenous

Question 8

What is herd immunity?

Answer 8

It is when individuals who are not immune to a pathogen are protected from exposure by the large amounts of immune individuals within the community

Question 9

When does pathogen spread stop?
(In relation to infection and critical threshold)

Answer 9

When P(infection)<critical threshold

threshold is pathogen & population specific

Question 10

Higher pathogenicity is associated with ____ critical threshold?

Answer 10

Higher

Question 11

What type of vaccines typically completely block infections?

Answer 11

Live attenuated

Question 12

Does a vaccine protect a person from infection or from severe disease?

Answer 12

Mostly protection from severe disease

Question 13

How do vaccines protect a person from severe disease?

Answer 13

1) Vaccines are usually delivered IV/IM (cos its easier) but many pathogens infect mucosal sites
- localised dmg limited by systemic immunity

2) Systemic vax → ↓no. pathogens in bodily secretions → ↓ transmisibilty

3) Hybrid immunity
- vax + recovery from mild infection
→ ↑ immunity + longer term

Question 14

What are 3 variables that complicate public vaccination policy?

Answer 14

1) Poverty/ social structure/ politics/ infrastructure
2) costs
3) public complacency and mistrust

Question 15

What are some requirements for an effective vaccine?

Answer 15

1) Safety
2) Induce protective immunity
3) Long-lasting protection
4) Low cost
5) Genetic stability
6) Storage stability
7) Delivery (Oral/needle)

Question 16

What are the 5 types of vaccines in order of decreasing safety but increasing efficacy?

Answer 16

1) Live attenuated (mimic natural infection)
2) Killed/dead viral pathogens
3) Pseudoviruses/virus-likes proteins
4) Viral-proteins and peptides sub-unit vaccines
5) DNA/RNA vaccines

Question 17

What is the relationship between vaccine safety and efficacy?

Answer 17

Inverse/negative relationship

Question 18

What are 2 examples of vaccine cocktails?

Answer 18

1) MMR/MMR-V
2) 6-in-1 (Diptheria, Tetanus toxoid, acellular Pertussis, Haemophilus influenzae B, Polio, Hep B)

Question 19

What are some limitations of live attenuated vaccines?

Answer 19

1) need to ensure 0 contamination
2) hazardous production
3) possible reversion to virulence*
4) req. proper refrigeration
5) not safe for immuno-compromised

Question 20

What are some limitations of killed pathogens vaccines?

Answer 20

1) need to ensure successful killing
2) adverse effects (eg. TAB → fever malaise, whole cell pertussis → febrile convulsions)

Question 21

What are some limitations of purified component vaccines?

Answer 21

1) tedious prod. and purification
2) expensive
3) low yield
4) need adjuvant/carrier

Question 22

What are some routes of vaccine administration?

Answer 22

1) Hypodermis
2) Transcutaneous
3) Oral
4) Nasal

Question 23

What are the differences between Mucosal and Systemic vaccination?

Answer 23

Mucosal:
- CD4+ > CD8+
- Nasal/oral administration
- prevents both initial stages and blocks development
- BOTH IgA and IgG
- induces local and systemic immune response
- immunity @ distant mucosal sites (via homing receptors

Systemic:
- CD8+ > CD4+
- Needle (cross-contamination + training)
- block disease development only AFT pathogen cross mucosal barrier and establish infection
- only IgG
- only systemic immunity

Question 24

Why aren’t all vaccines for respiratory infection made for mucosal administration?

Answer 24

It’s not always possible based on form and f(x) of the vaccine construct.

Question 25

What is an adjuvant?

Answer 25

An agent w/o any specific antigenic effect but may be immunogenic to ↑ response to vaccines

Question 26

Which form of vaccines require adjuvants?

Answer 26

Purified proteins and sub-units vaccines

Question 27

Why do purified proteins, sub-units, vaccines require adjuvants?

Answer 27

because they are poorly immunogenic and readily degraded by proteolytic system

Question 28

What are the some possible functions of adjuvants?

Answer 28

1) ↑Immunogenicity
2) Prolong exposure to the immune system
3) Ag sparing (↓ Ag/dose)
4) Dose sparring (↓doses needed)
5) Stimulate innate immunity → augment adaptive response

Question 29

What are the 2 types of vaccine adjuvants?

Answer 29

1) Mineral salts (Aluminium salts but can cause Al intoxication)
2) Emulsions (allows slow Ag release but ↑toxicity)