Vaccination

What are the two types of active immunity?

• Natural: contract COVID and manufacture specific antibodies

• Artificial: COVID vaccine enables production of specific antibodies

What is active immunity?

Body produces specific antibodies when exposed to a foreign antigen (naturally or artificially)

What are the two types of passive immunity?

• Natural: antibodies enter blood stream across placenta or breast milk

• Artificial: antibodies injected into bloodstream (tetanus injections)

What is passive immunity?

Individual receives antibodies they did not produced themselves 

Why is artificial passive immunity necessary?

• Antibodies are injected to immediately establish immunity

• Faster than initial immune response

What are the disadvantages of passive immunity?

• Short-lived as antibodies are broken down and excreted

• No memory cells: antibody levels cannot increase rapidly on secondary exposure to antigen

What is Vaccination?

• Artificial introduction of pathogens / antigens to enable body cells

• Produce appropriate antibodies without being harmed by pathogen

What is immunisation?

• Programming immune response

• Developing immunity to a pathogen naturally or artificially

• Enables cells to respond rapidly to infectious micro-organisms

What are vaccines?

• Artificial active immunity

• Antigen preparation used in artificial immunisation

How do vaccines work?

• Artificial introduction of a specific weakened or inactive part of a pathogen (antigen)

• Encourages immune response / creation of antibodies and memory cells (remain in body for a long time)

• On subsequent exposure to pathogen pre existing memory cells trigger rapid production of specific antibodies

• Response is more rapid and larger than initial exposure

• Individual experiences less severe symptoms or no symptoms

What are the types of vaccines? (LIST)

• Live attenuated

• Inactivated

• Sub-unit

• Toxoid

What are live attenuated vaccines?

• Living attenuated micro-organisms with reduced virulence

• Reduced ability to produce disease

• Polio, Rubella, Measles, Mumps

What are inactivated vaccines?

• Dead micro-organisms

• Immunity is shorter lived than live attenuated vaccines

• Cholera, Typhoid, Whooping Cough

What are toxoid vaccines?

• Inactivated bacterial toxins

• Diphtheria and Tetanus

What are sub unit vaccines?

• Isolated fragment of a micro-organism

• HPV and Hepatitis B

What are conjugate vaccines?

Pieces of the bacterial coat and carrier protein combined

What are recombinant vaccines?

• Genetically engineered vaccines

• Virus protein is inserted into another virus

At what age are the first vaccines given and why?

• 2 months

• Childs blood contains mothers antibodies via placenta or breast milk

• Childs immune system needs time be activated to prevent them from contracting the disease

What is the exception to the vaccine schedule?

Hepatitis B vaccination due to risk of child being infected during birth

Why are secondary vaccinations (boosters) necessary?

• Antibody levels from primary response (first vaccination) will decline

• Booster stimulates a secondary response

• Memory cells react rapidly to second exposure resulting in higher longer lasting levels of antibodies and additional memory cells

Why are booster shots given 2 months after initial vaccine?

• 2 month period allows antibodies in blood to be eliminated

• Antibodies present in blood will eliminate vaccine material before more B-cells can be activated and new memory cells created

What is heard immunity?

Resistance to spread of contagious disease in a population if a sufficiently high proportion of individuals are immune to the disease (vaccination)

What is required for herd immunity?

High portion of individuals need to be immunised

What are health factors in regards to vaccines?

• Allergic reactions (reaction to medium vaccine was cultured in)

• Preservatives

What are economic factors in regards to vaccines?

• Expensive / high cost

• Commercialisation

What are Autoimmune diseases?

• Excessive activity of specific antibodies and t-lymphocytes

• Overactive immune response against tissues and cells normally present in body

How are autoimmune diseases treated?

• Immunosuppressive drugs

• Decreases immune response