vaccinations

Question 1

what type of immunity is provided by vaccinations?

Answer 1

artificial active immunity

Question 2

how do vaccinations work?

Answer 2

vaccinations stimulate the adaptive immune response to produce antibodies through the administration of a non-pathogenic form of a pathogen without causing the disease, thereby protecting the host from future infections by the same/similar pathogens

Question 3

what virus causes smallpox?

Answer 3

Variola major or Variola minor

Question 4

how is smallpox transmitted?

Answer 4

person-to-person contact and through saliva droplets

Question 5

what is ring vaccination?

Answer 5

vaccinate people immediately in contact with the infected person, reducing the chances of transmission

Question 6

outline the events which occur after vaccination

Answer 6

1. the vaccine contains either the attenuated or modified pathogen/antigen
2. the modified pathogen/antigen is phagocytosed by an antigen-presenting cell (APC)=dendritic cell, macrophage
3. antigen is processed by APC and presented on Class II MHC on cell surface membrane to naive CD4 T cells
4. naive CD4 T cells with receptors that recognise the antigen binds to APC
5. this activates the naive CD4 T cell which then proliferate and differentiate to become many antigen-specific helper T cells and memory cells
6. naive B cell which recognises and binds to the same antigen, presents the antigen to helper T cells
7. B cell is activated
8. helper T cells releases cytokines which completes the activation of B cells
9. B cells proliferate and differentiate to form antigen-specific plasma cells and memory cells
10. plasma cells secrete antibodies against pathogen
11. memory B and T cells formed provide long-term protection against infection with the same pathogen/antigen

Question 7

what factors determine the effectiveness of vaccines? (five)

Answer 7

1. able to stimulate the desired immune response
2. safe to use with minimal side effects
3. highly stable (quality doesn’t deteriorate over time and it is easily stored and transported)
4. easy to administer which ensures an adequate amount would trigger an immune response
5. low cost (can be mass produced at an affordable price)

Question 8

what are the benefits of vaccinations?

Answer 8

1. safe as it stimulates the immune response without causing the disease
2. provides long-term immunity and protection from the disease
   => results in a rapid and stronger immune response to combat the infection by the same pathogen in the future
3. decrease the spread of the disease/completely eradicate the disease through herd immunity/ring vaccinations to prevent epidemics and pandemics
4. simpler, cheaper and effective way to prevent illness in large numbers of people compared to high costs of quarantine, treatment, long-term care

Question 9

define herd immunity

Answer 9

a situation when a significantly large proportion of a population is vaccinated and developed immunity against the disease (85%)

Question 10

what are the risks of vaccinations?

Answer 10

1. may require administration of booster shots to stimulate immunological memory for the body to produce more memory cells
2. stronger adverse (allergic) reactions
   => eg rashes, abdominal pain, nausea, vomiting, swelling of throat, difficulties breathing etc
3. possible risk of incomplete attenuation of pathogen will cause disease to develop in the individual, posing a risk to immunosuppressed individuals who cannot combat the disease
4. possible risk of attenuated pathogen reverting to its virulent form, causing disease to develop