Past Exam Questions Mod 3

Question 1

Detail 3 reasons new vaccines and vaccine technologies are needed?

Answer 1

1. address emergung diseases and pandemics
2. still need vaccines for existing diseases e.g. HIV
3. some vaccines don’t have ideal immunisation schedules e.g. multiple boosters
4. some current vaccines offer suboptimal protection e.g. wanes after 5 years

Question 2

list 3 benefits of vaccination

Answer 2

1. disease control
2. prevention of unvaccinated populations
3. protection against related diseases + cancer

Question 3

describe 6 vaccines technologies

Answer 3

1. Inactivated Vaccines
   - consists of killed virus particles
   - often requires boosters
2. Live Attenuated Vaccines
   - uses a weakened form of the virus
   - vaccines create a strong + long-lasting immune response with one or two doses
3. Subunit Vaccines
   - uses antigens (small parts) of an organism that are known to stimulate the immune system
   - cannot revert to virulent form
4. Toxoid Vaccines
   - consists of a toxin from a particular bacteria that has been made harmless but elicits an immune response against the toxin
   - cannot cause disease
   - generally a weaker immune response requiring boosters
5. Viral Vectored Vaccines
   - vaccine uses a harmless virus as a vector to deliver important instructions to help your body learn how to recognise + fight the germ that causes the disease
   - can be grown to high titres
6. mRNA Vaccines
   - uses a small piece of mRNA from pathogen that causes the disease
   - cells use instructions to make antibodies
   - cannot revert to virulent form

Question 4

What is drug repurposing?

Answer 4

Drug repurposing involves finding new therapeutic uses for existing drugs that are already approved for other conditions. This approach can save time and costs compared to developing new drugs from scratch, as the safety profiles of these drugs are already well established.

Question 5

List and briefly describe the TWO (2) major approaches to drug repurposing.

Answer 5

1. known molecule acting via a new target/mechanism for a new indication (“Drug centric”)
2. known molecule acting via a known target/mechanism for a new indication (“target centric”)

Question 6

Discuss THREE (3) benefits of drug repurposing compared to conventional development of a new
chemical or new biological entity.

Answer 6

1. lower risk
   - these drugs already have an established toxicity and safety profile so they are much less likely to cause adverse effects than a new drug might
2. shorter time to market
   - the drug/ compound might be able to enter the development path at a more advanced stage than a new drug due to their previous testing etc
3. lower cost of development
   - some/most preclinical testing and some early clinical testing may not need to be repeated

Question 7

Describe TWO (2) potential barriers to successfully applying a drug repurposing strategy

Answer 7

1. Intellectual Property issues
   - sometimes owners of the patent for the original drug have anticipated future drug repurposing for their compound and have claimed in under their patent - this affects novelty
2. Data Issues
   - if the previous studies were done a while ago they might not meet the current regulatory requirements
   - sometimes it could be hard to gain access to proprietary data (require licensing)

Question 8

List ONE (1) example of the application of a drug repurposing approach to drug development.
[1 mark]

Answer 8

sildenafil - viagra

developed as an anti-angina drug
- repurposed for its secondary effects to treat erectile dysfunction

Question 9

Discuss the FOUR (4) main challenges associated with vaccine development.

Answer 9

1. immunogenicity/efficacy
2. safety
3. regulatory hurdles
4. manufacturing issues