Preventing + treating disease Flashcards
What is active immunity?
Immune system makes own antibodies after exposure to pathogen’s antigens.
Long-term protection –> memory cells produced
Example of natural active immunity
Resistance to common cold –> secondary immune response
Example of artificial active immunity:
Vaccinations (polio, hepatatis B)
What is passive immunity?
When individual is given antibodies made by different organism
Immediate immunity
Short-term protection –> antibodies broken down + memory cells not produced
Example of artificial passive immunity:
Antibodies from 1individual extracted + injected in
bloodstream of another individual.
Example of natural passive immunity:
Baby receiving antibodies from mother via breastmilk/placenta during pregnancy
Define vaccination:
Introduction of pathogen’s antigens into body via injection.
Develop artifical active immunity.
Attenuated pathogen strain used
How does vaccination provide immunity?
Vaccine injected into blood
Stimulates primary immune response to produce abtobodies againbst pathogen
Memory cells capable of recognising anotgens produced
Second exposure = memory cells rapidly divide tio plasma cells
Plasma = antibodies
Pathogen destroyed
What factors determine how successful a vaccination will be?
Availability: suitable vaccines = affordable + available in large amounts for mass immunisation
Minimal side effects: fewer side effects = better public acceeptance
Infrastructure: necessary resources for producing, storing vaccine
Administration: proper + timely vaccine administeration -> trained workers
Herd immunity: goal to vaccinate majority of population to achieve herd immunity
Define herd immunity:
Large proportion of population vaccinated = protect those not vaccinated
fewer individuals = infected –> most immune to disease + cannot transmit pathogen onto others
What are advantages of mass vaccination?
Help prevent epidemics/pandemics
Important as impossible to vaccinate every indivdual within large population
Why might vaccines not eliminate disease?
Individual immunity failures: weak immune system = cannot withstand vaccines
Pre-immunity infection: may contact disease post vaccination but before immuntiy develops –> potential disease resevoir.
Pathogen mutation + antigenic variability: rapid antogenic changes due to frequent mutations –. make vaccines ineffective –> immune system no longer recognise pathogen’s new antigen.
Pathogen variety: number of pathogen variants –> make developing universally effective vaccine = impossible
Vaccine objections: personal/ethical reasons
What is antigenic variability?
Relies on introducing pathogen’s antigens into body to stimulate immune response.
Some pathogen can change antigens
Difficult to develop vaccines against some pathogens –> no longer recognised by immune system.
Memory cells produced from vaccines against 1 strain not recognise antigen from another strain.
.: Vaccines changed frequently
How to antibiotics work?
Drugs that kill/inhibit growth of bacteria
Target bacterial enzymes + ribosomes used in metabolic reactions–> do not damage cells.
How do antibiotics affect bacteria?
Preventing synthesis of bacterial cell walls
Disrupting protein activity in cell membrane
Disrupting enzyme action
Preventing DNA synthesis
Preventing protein synthesis
Why do antibiotics not work against viruses?
Lack cell strictures + rely on host cells to carry out metabolic reactions
Antibotucs cannot target + disrupt reactions
Antibiotics unable to reach viruses –> inavde organism’s own cell.
What are some sources of medicine?
Penicillin: antobiotic extracted from type of mould
Aspirin: painkiller based on compounds from willow bark
Prialt: pain-killing drug derived from venom of cone snail
Some plants undiscovered which can treat incurable diseases.
–> potential sources of new medicines protected by maintaining biodiversity
What bacterias have developed antibiotic resistance?
MRSA –> cause wound infections + resistant to multiple antibiotics.
C. difficile –> bacteria infect digestive systme + survive/reproduce in prescence of antibiotics.
What can help reduce development of antibiotic resistance?
- Choosing appropriate antibiotics for treatment: tested against bacterium strains –> effective in treating disease
- Using antibiotics only when needed –> only for bacetrial infections
- Avoid use of wide-spectrum antibiotics: specific antibiotics
- Ensure patients take complete course of treatment: ensure all bacteria killed
- Avoid use of antibiotics in farming: reduces chance of bacteria being resistant
What are some sources of medicines?
Penicillin: antobiotic extracted from type of mould
Aspirin: painkiller based on compoudns from willow bark
Prialt: pain-killing drug dervied from venom of cone snail
Digoxin: from foxgloves -> treat atrial fibrillation + heart failure
What is the future of medicine?
Pharmacogenetics: personalised medicine –> tailored to individual DNA
–> genome analysed before any treatment –> more likely to be effective + less likely to cause side effects.
Synthetic biology: use of genetic engineering to develop artifical proteins, cells +
microorganisms
–> bacteria + mammals modified to produce therapeutic drugs to treat certain diseases
