Vaccines & drugs

• VACCINATION


  A proactive approach to prevent diseases rather than treating them after infection.

  • they work against bacteria and viruses.

  
• How VACCINATIONS Work:

  • By introducing DEAD / INACTIVE pathogens into the body.
  • So they aren't strong enough to cause a disease.
  • They carry the same ANTIGENS, it causes the WBCs to produce ANTIBODIES to develop immunity.
  • The lymphocytes stay in the body as MEMORY CELLS:
  • If the actual pathogen was to ever enter the body.
  • They would rapidly produce a LARGE VOLUME of antibodies to destroy the pathogens and prevent illness.

  The MMR VACCINE is an example that combines weakened versions of the viruses causing measles, mumps, and rubella.

  
• Advantages of vaccinations:

  • Control and destruction of diseases; Examples include:
  • smallpox
  • polio
  • measles
  • whooping coughs
  • Preventions outbreaks through herd immunity, so it doesn't kill lots of people.
• Disadvantages of vaccinations:

  • Not always guaranteed full immunity:
  • Some vaccines offer varying degrees of protection
  • Booster shots may be needed
  • Risks of side effects:
  • Rare, mild reactions like soreness / fever can occur.
  • Serious reactions like seizures.
• PAINKILLERS:


  Drugs that relieve the symptoms of disease such as PAIN and FEVER.

  • But DO NOT target the cause of the disease.

  Examples include ASPIRIN and PARACETAMOL.
• ANTIBIOTICS


  directly Kills ONLY BACTERIA or prevents their REPRODUCTION.

  • This stops the infection at its source.
• The Science Behind ANTIBIOTICS:

  • They only target BACTERIAL infections by killing bacteria cells.
  • They are ineffective against viruses:
  • viruses reproduce inside body cells.
  • It's difficult to destroy the virus without destroying the healthy cell.
  • They recognise bacteria by the unique ANTIGENS on their surface and disrupt their life processes.
  • The correct antibiotic must be matched with the right bacterial infection to be effective as they are SPECIFIC to certain bacteria.
• Bacteria can EVOLVE, leading to ANTIBIOTIC RESISTANCE:


  This makes some antibiotics LESS EFFECTIVE or even useless against these resistant bacteria.

  • If the resistant bacteria reproduce and spread, it can become difficult to treat and can lead to a SERIOUS INFECTION.

  An example of this is MRSA (a bacteria that EVOLVED to become resistant to the antibiotic METICILLIN).
• PENICILLIN


  Comes from MOULD and is used as an ANTIBIOTIC.
• In the UK, chickens are vaccinated against salmonella bacteria to reduce the number of cases of food poisoning in humans as:

  • fewer pathogens in food
  • so fewer bacteria are ingested
  • so fewer toxins produced
• A vaccine against malaria could reduce the spread of the disease as:

  • it makes people immunes and they do not develop the disease
  • so fewer infected people to pass pathogens on.
• The differences between antibody production after the vaccine injection and after exposure to the measles virus:

  • Higher concentration of antibodies produced from WBCs, from 0.8 to 7.2
  • antibodies produced sooner, as WBCs recognise pathogen.
  • antibodies produced quicker from memory cells
  • Antibodies stay in higher concentration for longer from production of specific antibodies.

  
• Whether to make the chickenpox vaccination free to all children, the government needs to consider factors like:

  • cost to the NHS / goverment
  • money saved through not treating people with chickenpox
  • how effective the vaccine is
  • severity of the disease
  • less effect of disease on people with weaker immune systems
• A vaccine prevents people becoming ill with salmonella food poisoning by:

  • antigen in vaccine stimulates WBCs
  • to produce specific antibodies
  • so if the person ingests salmonella
  • so on secondary exposure to antigen, WBCs produce the correct antibodies faster / in larger quantities and memory cells
  • so toxins produced by the bacteria, don't reach high enough concentrations to make the person have symptoms
• The controlled variables that's used are:

  • concentration of antibiotic
  • type of disc
  • type of filter paper
  • size of disc
  • temperature
  • time - kept for 3 days

  
• Antibiotics cannot be used to treat HIV infections as:

  • HIV is not a bacterium, but a virus.
  • antibiotics only kill bacteria, not viruses
  • viruses are inside cells and it's difficult to get the antibiotic to the virus.
• The concentration of live bacteria in the body continued to increase after starting the course of antibiotics because:


  • only a few bacteria killed, so live bacteria continues to reproduce.
  • it takes time for antibiotic to travel through the body.
  • it takes time for antibiotic to work.

  
• Doctor do not give antibiotics to patients with minor infections:


  • to reduce bacteria developing
  • they will get better without taking any antibiotics
  • some infections are caused by viruses
• Control variables:

  • size / shape / type of paper disc
  • concentration of antibiotic
  • amount of antibiotic
  • incubation time
  • incubation temperature

  
• One disc was soaked in water:

  • to check that the disc / water did not have an effect
  • to make sure it was the antibiotic that had an effect

  
• herd immunity:


  Widespread vaccination campaigns can prevent outbreaks of disease (epidemics).

  • If a large enough portion of the population is vaccinated, it makes the spread of disease from person to person unlikely.
  • As a result, the whole population becomes protected - not just those who are immune.

  
• Medication:


  A drug that's used to:

  • relieve symptoms

  or

  • cure disease
• The Science Behind ANTIBIOTICS:


  They only target BACTERIAL infections by directly killing bacteria cells.

  • They are ineffective against viruses:
  • viruses are so different to bacteria, so the antibiotic can't do anything to them.
  • Antibiotics wouldn't be abled to find them, as viruses hide and reproduce inside body cells.
  • So it's difficult to destroy the virus without destroying our own cell as well.
  • They recognise bacteria by the unique ANTIGENS on their surface and disrupt their life processes.

  
• There are loads of different antibiotics and each antibiotics can only kill certain types / strains of bacteria:

  • so doctors sometimes have to do a test first to find out which type of bacteria you have.
  • Before they can prescribe an antibiotic, to be effective as they are SPECIFIC to certain bacteria.

  
• Measures that could help to reduce the spread of antibiotic resistance:


  • completing the FULL COURSE of antibiotics even if the patient is feeling better.
  • only using them when symptoms are SERIOUS.

  (eg. Not for small coughs)

  
• ASPIRIN



  Comes from WILLOW BARK and used as:

  • A PAINKILLER
  • to LOWER FEVER

  
• DIGITALIS



  Comes from the plant "FOXGLOVES".

  • Used to treat HEART CONDITIONS like heart failure.