Back to 课程

Biology AS CIE

0% Complete
0/0 Steps
  1. 1-cell-structure
    10 主题
  2. 2-biological-molecules
    19 主题
  3. 3-enzymes
    13 主题
  4. 4-cell-membranes-and-transport
    16 主题
  5. 5-the-mitotic-cell-cycle
    8 主题
  6. 6-nucleic-acids-and-protein-synthesis
    9 主题
  7. 7-transport-in-plants
    11 主题
  8. 8-transport-in-mammals
    16 主题
  9. 9-gas-exchange
    6 主题
  10. 10-infectious-diseases
    6 主题
  11. 11-immunity
    10 主题
课 11, 主题 2
In Progress

11-2-antibodies-and-vaccination AS how-vaccines-work

课 Progress
0% Complete

Exam code:9700

How vaccines work

  • A vaccine is a suspension of antigens that are intentionally put into the body to induce artificial active immunity 

    • A specific immune response where antibodies are released by plasma cells

  • There are two main types of vaccines:

    • Live attenuated

    • Inactivated

  • Vaccines are administered either by injection or orally (by mouth)

    • When a person is given a vaccine they have been given a vaccination (they are said to have been vaccinated)

  • The vaccinations given by injection can be into a vein or muscle

  • Vaccinations produce long-term immunity as they cause memory cells to be created

    • The immune system remembers the antigen when reencountered and produces antibodies to it, in what is a faster, stronger secondary response

Diagram of how an immune response works: injection, antibody activation, lymphocyte multiplication, specific antibodies, memory cell creation.
The process of vaccination and development of long term immunity

Live attenuated vaccines

  • Live attenuated vaccines contain whole pathogens (e.g. bacteria and viruses) that have been ‘weakened

    • These weakened pathogens multiply slowly allowing for the body to recognise the antigens

    • They trigger the primary immune response (plasma cells to produce antibodies)

    • These vaccines tend to produce a stronger and longer-lasting immune response

Inactivated vaccines

  • Inactivated vaccines contain whole pathogens that have been killed (‘whole killed’) or small parts (‘subunit’) of the pathogens (e.g. proteins or sugars or harmless forms of the toxins – toxoids)

    • As inactivated vaccines do not contain living pathogens they cannot cause disease, even for those with weak immune systems

    • However these vaccines do not trigger a strong or long-lasting immune response like the live attenuated vaccines

      • Repeated doses and / or booster doses are often required

Examiner Tips and Tricks

Remember vaccines trigger the primary immune response (T-helper cells trigger plasma cells to secrete specific antibodies), which leads to the production of memory cells. This will give a faster and greater response (a higher concentration of antibodies in a shorter period of time) during the secondary response.

Responses

您的邮箱地址不会被公开。 必填项已用 * 标注