Autoimmunity and Vaccinations

What is an *autoimmune disease*?

When the body attacks itself, the immune system damages body cells as a result

What cells are attacked, and by what?

Self-antigens are attacked by antibodies, T-cells and B-cells

What are self-antigens?

the antigens present on the organism’s own cells

What does self-antigens being attacked cause?

Self-antigens are treated as foreign antigens and launches an immune response on the body’s own tissue

Name 2 examples of autoimmune responses

Lupus

Rheumatoid Arthritis

What forms the surface antigen and what does it do?

Glycoproteins and glycolipids form surface antigens that enable the immune system to determine whether the cell belongs to the body or if it is foreign

What is active immunity

Long term circulation in blood

What is passive immunity

Temporary circulation in blood

What is natural active immunity?

Immunity that is caused by an infection – antibodies remain in the blood permanently

What is natural passive immunity?

Anti-bodies are provided to a baby across placenta pre-birth, and in breast milk in colostrum – anti-bodies only last a few months

What is artificial active immunity?

Immunity that is cause by vaccination / immunisation – antibodies remain in the blood permanently

What is artificial passive immunity?

Anti-bodies are injected in to a person while they have an infection – they only last a few months

What differentiates between the different types of immunity?

Define *vaccine*

a ^^suspension of **antigens**^^ that are intentionally put into the body to ^^induce **artificial active immunity**^^

Name the 3 types of vaccine

1. Inactivated
2. Live attenuated
3. Subunit

What is inactivated vaccine

The whole pathogen is given but it cannot reproduce, DNA is not able to replicate and its metabolic processes are stopped

What is live attenuated vaccine?

This only stops the reproduction of the pathogen

What is subunit vaccine?

Only a part of the antigen is given

What are 3 challenges of vaccines

1. Antigenic variation
2. Poor response
3. Adjuvants reaction

What is antigenic variation?

A variation in the antigens of pathogens causes the vaccine to not be able to trigger an immune response.

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Diseases caused by eukaryotes can have too many antigens on their cell surface membrane, which makes it difficult to produce vaccines which prompt a quick immune response

Why could people have a poor response to vaccines

People could be malnourished and this not produce the antibodies or proteins

Or their immune system could be defective

What are adjuvants?

Other things in vaccines. eg aluminium

What is herd immunity?

**Herd immunity** arises when a ^^**sufficiently large proportion of the population has been vaccinated (and are therefore immune)**^^ which ^^makes it difficult for a pathogen to spread within that population^^