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Science of a vaccine


What are vaccines?

  • Inactivated pathogens - vaccines work by introducing an inactivated pathogen/part of pathogen into the body

  • Triggers - the pathogen will trigger an immune response similar to that generated by a natural infection

  • Artificial active immunity - hence, vaccines lead to the development of natural antibodies against the targeted disease


How are vaccines made and administered?

  • Types of vaccines - vaccines may contain a liver microorganism, a dead one, an attenuated one, a toxin or some surface antigens

  • Administration - vaccines can be given through an intramuscular injection or via oral ingestion (such as the polio vaccine)

  • The COVID-19 vaccines - these range from RNA sequences coding for proteins of the virus, surface antigens or attenuated microorganisms

  • Effectiveness - some vaccines may only require one single shot to give lifetime protection, while others need boosters to stimulate further immune responses

Advantages and disadvantages of vaccines

  • Advantages

    • An easy and safe way of immunizing the population against deadly or very severe diseases such as COVID-19

    • Vaccines have improved the quality of life of the population and have led to the eradication of deadly diseases like smallpox

  • Disadvantages

    • Some people may not develop an immune response to the vaccine, hence not becoming immune to the disease

    • Although unlikely, some inactivated viruses can undergo a shift back to their active form, leading to infection

Why are vaccines important?

  • Providing population immunity

  • Disease control and eradication

  • Relatively cheap to manufacture

  • Safe for most of the population

  • Allow travel without disease spread

  • Prevents disease strain on the NHS


"Has the production of the vaccines against COVID-19 been 'too fast' and 'rushed'?"

Top interview tips

  • Take a moment to think - this is a very controversial topic so make sure to think which ideas are best to include

  • Prove your knowledge - show that you know the science behind a vaccine and how it is hard to "rush" science

  • Cover both sides - make sure to mention that you are aware of both sides of the issue and why some people might find those claims true

  • Stay neutral - as it is a controversial topic, try to keep your own opinions as well and only present reasoned arguments


  • Brush up your knowledge of the immune system - look at your A-Level notes or at quick YouTube videos

  • For controversial topics like this - stay neutral and only state the science and not your opinions

  • For more information - you can use our website


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