Vaccines

Question 1

types

Answer 1

DNA vaccines
Subunit
Inactivated
Attenuated

Question 2

Examples of subunit vaccines

Answer 2

Hepatitis B
Tetanus
Diphtheria

Question 3

What is a subunit vaccine

Answer 3

Vaccine containing purified components of the virus

Example components include the surface antigen

Question 4

What is a DNA vaccine

Answer 4

(potentially in the future)
Usually a harmless virus which has a gene for a protective antigen spliced into it
This protective antigen is generated within the vaccine recipient and elicits an immune response

Question 5

Advantages of DNA vaccine

Answer 5

Plasmids are easily manufactured and do not replicate
DNA is stable and sequencing may be changed
Temperature extreme are resisted, therefore it is easily transported and stored
Cheap

Question 6

Disadvantages of DNA vaccine

Answer 6

Plasmids could integrate into the host genome

Immunological tolerance

Question 7

Examples of inactivated vaccine

Answer 7

Polio (Salk)
Rabies
Hep A
Influenza
Preparations of wild type virus

Question 8

Why is formalin added to inactivated vaccine

Answer 8

Chemical treatment with formalin causes virus to by nonpathogenic due to cross-linking of viral proteins

Question 9

Advantages of inactivated vaccine

Answer 9

Sufficient humoral immunity if boosters given
Good for immunosuppressed patients
No mutations of virus
Good for those living in tropical areas

Question 10

Disadvantages of inactivated vaccine

Answer 10

Some do not increase immunity
Boosters are required
Expensive
Potential failure of viral inactivation process
Little local immunity

Question 11

What is an attenuated vaccine

Answer 11

Live virus particles grow in the vaccine recipient
However, these particles do not cause disease as the virus has been mutated to a form that is non-pathogenic e.g. the virus tropism has been altered

Question 12

Examples of attenuated vaccine

Answer 12

Polio (Sabin)
Mumps
Measles
Rubella (MMR)
Varicella
Rotavirus
Yellow fever

Question 13

Advantages of attenuated vaccine

Answer 13

Activates all phases of the immune system
It stimulates antibodies against multiple epitopes
Provides cheap and fast immunity
Has the potential to eliminate the wild type virus from the community
Easily transported

Question 14

Disadvantages of attenuated vaccine

Answer 14

If the mutation fails then the virus will revert to its virulent form
Potential spread of the mutated viral form
Do NOT give to immuno-comprimised patients
Not good for those living in tropical areas