Vaccines

Question 1

Why Do We Use (Need) Vaccines?

Answer 1

Prevention: Vaccines protect against infectious diseases by stimulating the immune system to recognize and fight pathogens without causing the disease.

Herd Immunity: Widespread vaccination reduces the spread of disease within a population, protecting those who cannot be vaccinated (e.g., due to medical reasons).

Disease Eradication: Vaccines have led to the eradication of diseases like smallpox and the near-elimination of others, such as polio.

Question 2

How Does Vaccination Work?

Answer 2

Introduction of Antigen: Vaccines introduce a harmless component of the pathogen (antigen) to the body.

Immune Response Activation: The immune system recognizes the antigen as foreign and mounts a response by producing antibodies and memory cells.

Immunity Development: Upon subsequent exposure to the actual pathogen, the immune system responds more rapidly and effectively, preventing or reducing illness.

Question 3

Types of vaccines

Answer 3

1.Live Attenuated Vaccines:
Take virus and grow it in other than human cells e.g. monkey cells. To get to monkey cells, the virus needs to mutate and will not be pathogenic to human host any more.
Contain weakened forms of the pathogen. They mimic natural infection and induce strong immunity.
Recombinant DNA technology, we can either mutate or replace a virulent gene or delete the gene responsible for virulence, so the virus can no longer be pathogenic, but still have all the other proteins that antibodies can recognize and bind to.

2.Inactivated Vaccines:
Virus is inactivated with UV, chemicals or heat and then injected.
They cannot cause disease but still provoke an immune response.

3 and 4. Recombinant and Conjugate Vaccines : Contain only parts of the pathogen (e.g., proteins or sugars) (e.g., HPV vaccine). They focus on the essential antigens, reducing the risk of side effects.

5.Toxoid vaccines:
Contain inactivated bacterial toxins (toxoids)
Protects against toxin-mediated infections
but these toxoids were not highly immunogenic.
Adjuvants were discovered to boost the immune response by attracting the immune system (Changes the physical state particulate – engulfable.
2.Creates an inflammatory environment)

Question 4

Modern vaccines

Answer 4

1.Viral vector vaccines
Use a harmless virus to deliver genetic material coding for a pathogen’s protein

2.RNA vaccines
Use messenger RNA to instruct cells to produce a viral protein, triggering an immune response

3.Nucleic acid vaccines: DNA
Plasmids that have been manipulated to contain a gene encoding a viral antigen

Answer 5

Adjuvants: Substances added to vaccines to enhance the immune response, making vaccines more effective and reducing the need for multiple doses.

Universal Vaccines: Development of vaccines targeting conserved regions of viruses (e.g., universal flu vaccine) to provide broader and longer-lasting protection.

Delivery Methods: Innovations like needle-free delivery (e.g., patches, inhalable vaccines) to increase accessibility and acceptance.

Therapeutic Vaccines: Designing vaccines not just for prevention but also for treating chronic infections and cancers by enhancing the immune system’s ability to fight ongoing diseases.