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Flashcards in Imms Deck (17):

Passive immunisation

- Natural: placental transfer of IgG
- Artificial


Artificial passive immunisation

- Treatment with immunoglobulin: human normal immunoglobulin and human specific immunoglobulin


Human normal immunoglobulin

- Contains all antibodies - protein extracted from pooled blood donations
- Post exposure prophylaxis: Hep A, measles, polio and rubella


Human specific immunoglobulin

- Selected blood donors with high antibodies against a specific organism
- Post exposure prophylaxis: Hep B, rabies, tetanus, VZV


Passive immunisation advantages and disadvantages

Advantages: gives immediate protection
Disadvantages: no immunological memory, incoming cells reject recipient and serum sickness (antibody recognised as foreign antigen, anaphylaxis)


Active immunisation

- Natural, exposed to the virus, you create a natural immunity to it
- Artificial


Artificial active immunisation

- Vaccinating against particular things
- First response (exposure): IgM
- Second response (exposure): IgG is likely changed response, much fast, stronger response. Probably clear the pathogen before you feel ill.


Contraindications of vaccination

- Temporary: febrile illness, pregnancy (no live attenuated vaccines)
- Permanent: allergy, immunocompromised (no live attenuated, might develop disease from vaccine)


Live attenuated vaccines

- Infect a cell in a lab either in a petri dish or non-human host
- Pathogenic organism is attenuated by repeated passage
- Risk that it can turn back into its original pathogenic organism
- Need a fridge
- Illicits a strong cellular and antibody response


Inactivated vaccines

- Stable and safer vaccines as you kill off the disease-causing microbe (use chemicals, heat or radiation)
- Not as strong an immune response: likely need boosters or adjuvant
- No fridge


Acellular vaccine

- Only part of cellular material (capsule, flagella, part of protein cell wall)
- Can be given to immunocompromised, cannot cause disease
- Not a very good immune response (may require booster)
- E.g. toixoid, take the toxins that induce illness and inactivate them with formalin, the immune system learns how to fight off the natural toxin and produces antibodies


Related organisms vaccines

- BCG, you vaccinate against Mycobacterium bovis to protect against Mycobacterium tuberculosis


Subunit vaccine

- Chop up pathogen so that only the antigens that best stimulate the immune system are used
- You get a broad spectrum in preparation for mutation and still get an immune response
- Chances of adverse reactions are low


Conjugate vaccines

- Polysaccharide coating of bacteria sometimes isn't recognised, particularly in immature immune systems
- You take away the coating and you add something else that the immune system can recognise
- Also, one vaccine can induce a strong response and the other one gains from it


DNA vaccines

- Hijacks body's own cellular system
- Inducing cells to make a foreign protein - genes for a microbe's antigens are used
- Invokes a strong antibody and cellular response
- Cannot cause the disease
- Easy to use and make
- No fridge
- None for humans yet



- If you don't get a particularly strong immune response from a vaccine you can enhance the immune response by adding an adjuvant
- Aluminium salts are an inflammatory reaction
or have a conjugate


Herd immunity

- Vaccinated individuals are less likely to be a source of infection to others
- Reduces the risk of unvaccinated individuals being exposed to infection