Vaccine

From The School of Biomedical Sciences Wiki
Jump to: navigation, search

07-blog-Vaccines.jpg[1]

A vaccine will allow an organism's immune system to develop an active immunity against a certain pathogen[2].

Vaccines are prepared from the causative agent of a disease, or a synthetic substitute treated to act as an antigen without inducing the disease.

The vaccine will mimic the process of a natural infection, however, the organism will not experience the effects of being infected by the pathogen[3].

In order to safely develop active immunity, the pathogen must first be altered in some way so that it will not be damaging to the target organism.

Processes that will render the pathogen harmless include:

The vaccine (altered pathogens) is then inserted into the target organism. Its Immune system will respond as the vaccine is seen as a threat. Theimmune response will behave naturally and the vaccine will be destroyed, however the Memory T and Memory B cells will remember the pathogen's antigen structure[5].

This will allow a rapid immune response if the organism ever comes into contact with the pathogen again[6]. However for T and B lymphocytes to develop it can take a few weeks, therefore it is possible that if someone is infected with the pathogen within a few weeks of getting them vaccinated it is possible for them to have symptoms of the disease[7][8].

Conjugate vaccines have been designed to immunise young children against Haemophilus influenzae type b (Hib). Hib contains a polysaccharide capsule made of polyribosyl ribitol phosphate (PRP) which is a T-independent antigen (thymus-independent) and is not immunogenic in children under the age of 4; therefore conjugate vaccines have been created to protect these individuals. The PRP capsule is covalently linked to a carrier protein, which attracts T cell help and, as a result, anti-PRP antibodies are produced. This means a second encounter of this polysaccharide on Hib would induce a rapid reaction to clear and destroy this pathogen[9].

References

  1. Vaccines [Internet]. Vaccines for World’s Most Deadly Infectious Diseases Unlikely. 2018 [cited 2018Dec10]. Available from: http://sitn.hms.harvard.edu/flash/2018/vaccines-worlds-deadly-infectious-diseases-unlikely/
  2. NHS.04/04/2014, How vaccines work, [Online]Available at: http://www.nhs.uk/conditions/vaccinations/pages/how-vaccines-work.aspx,[Accessed - 27/11/2014]
  3. U.S. Department of Health and Human Services.23/7/13, How Vaccines Work, [Online]Available at: http://www.vaccines.gov/more_info/work/ ,[Accessed - 27/11/2014]
  4. NHS.04/04/2014, How vaccines work, [Online]Available at: http://www.nhs.uk/conditions/vaccinations/pages/how-vaccines-work.aspx,[Accessed - 27/11/2014]
  5. U.S. Department of Health and Human Services.23/7/13, How Vaccines Work, [Online]Available at: http://www.vaccines.gov/more_info/work/ ,[Accessed - 27/11/2014]
  6. U.S. Department of Health and Human Services.23/7/13, How Vaccines Work, [Online]Available at: http://www.vaccines.gov/more_info/work/ ,[Accessed - 27/11/2014]
  7. http://www.cdc.gov/vaccines/hcp/patient-ed/conversations/downloads/vacsafe-understand-color-office.pdf
  8. http://www.cdc.gov/vaccines/hcp/patient-ed/conversations/downloads/vacsafe-understand-color-office.pdf
  9. Dominic F Kelly, E Richard Moxon, Andrew J Pollard. (2004) Haemophilus influenzae type b conjugate vaccines. Immunology. Vol.113(2), 163-174.
Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox