FA Vaccines

Question 1

What are Autogenous vaccine produced from?

Answer 1

A pathogen isolated from an infected animals in a flock/herd during a disease outbreak

Question 2

A well designed vaccine should be optimised which which 4 correct factors?

Answer 2

• Adjuvant
• Route
• Delivery system
• Schedule

Question 3

When considering vaccine strategies which factors need to be considered?

Answer 3

• Age
• Boosters/length of immunity
• Cost
• Herd immunity
• Vaccine type e.g. live, killed
• Single vs multiple vaccines

Question 4

Why does age need to be considered when giving vaccines?

Answer 4

• Neonates are poorly responsive versus need for protection at young age
• Maternal antibody may affect success of some vaccines

Question 5

What are adjuvants?

Answer 5

Compounds delivered with the antigen in a vaccine that help develop the immune response

Question 6

Name the most commonly used adjuvant

Answer 6

Aluminium salts

Question 7

Describe the steps in how adjuvants work

Answer 7

• Most adjuvants work by stimulating Antigen presenting cells
• Can modify response to Th1 or Th2
• Some promote antigen uptake or improve cell recruitment
• Aluminium-based adjuvants (Alum) also cause a ‘depot’ effect- antigen released over time from deposits of the adjuvant

Question 8

What is herd immunity?

Answer 8

Phenomenon by which vaccination of proportion of population gives protection to the whole population

Question 9

When are live microbes/vectors used in vaccines?

Answer 9

• Deliver recombinant or DNA vaccines

- Bacteria (Salmonella), viral (adeno & pox virus/vaccinia) can deliver to host cells

Question 10

What are nanoparticles?

Answer 10

Synthetic structures that can deliver antigens & adjuvant to host antigen presenting cells via nasal or oral route

Question 11

How do DNA vaccines work?

Answer 11

DNA vaccines incorporate into host nucleus & are transcribed and translated into antigen

Question 12

What some some different was vaccines can be administered?

Answer 12

Needle
Orally or nasally
Eye drops
Drinking water
Spray/inhalation
Gel drop
In ovo (birds)

Question 13

How is mass vaccination usually carried out i.e. in poultry flocks?

Answer 13

Parenteral delivery not cost effective

Drinking water and spray delivery increasingly used

Question 14

What are the advantages and disadvantages of re-usable vs disposable syringes?

Answer 14

• Re-useable syringes are often slightly more accurate, but are easily broken and require sterilisation.
• Disposable syringes vary in their design and remove the need to sterilise equipment.

Question 15

What type of vaccine can be added to the water supply?

Answer 15

Live attenuated vaccines

Question 16

When are gel drop vaccines used? What are the benefits of them?

Answer 16

• Modified spray vaccination-delivery via coloured edible gel
• Gel protects live vaccines and can incorporate adjuvant
• Increasing use in poultry-increase efficacy and stops chicks getting wet
• Bright colour via dye attracts chicks who are also hungry and thirsty so rapid ingestion

Question 17

Describe in ovo vaccines

Answer 17

Delivery into embryo in hatchery
Often delivers DNA vaccine
Some risk of increased chick mortality