Infection and response

• Vaccination


  Introduction of an antigen or a weakened or inactive form of a pathogen to generate immunity

  
• Lymphocyte


  The white blood cell responsible for antibody production

  
• Antibody


  A protein that binds to a specific antigen and triggers the pathogens to be destroyed

  
• Antibody production


  When a white blood cell called a lymphocyte produces antibodies
• Antigen


  A substance on a foreign cell or pathogen that triggers an immune response

  
• Memory cell


  A white blood cell that recalls the structure of a specific antigen to prevent the body from being infected a second time
• Herd immunity


  The resistance to the spread of a disease in a population which is due to the majority of individuals being immune

  
• Active immunity


  The process of exposing the body to an antigen or pathogen to generate an adaptive immune response

  
• Primary response


  The reaction of the immune system when exposed to a pathogen for the first time

  
• Secondary response


  The very quick reaction of the immune system when exposed to the same pathogen for a second time

  
• Antibiotic


  A chemical that kills or reduces the reproduction rate of bacteria

  
• Penicillin


  An antibiotic discovered by Alexander Fleming that is made from Penicillium mould

  
• Antibiotic-resistant strain


  A strain of bacteria that has mutated and is no longer treatable with standard antibiotics

  
• Painkiller


  A medicine which reduces the symptoms of disease but does not kill pathogens

  
• Antiviral drug


  A class of medication used to treat viral infections
• Penicillin


  An antibiotic discovered by Alexander Fleming that is made from Penicillium mould

  
• Digitalis


  A heart drug that originates from foxglove plants

  
• Aspirin


  A painkiller that originated from willow trees

  
• Pharmaceutical industry


  Businesses that develop and produce drugs for use in medicine and health care
• Toxicity


  The harmful effects of a drug
• Efficacy


  The effectiveness of a drug
• Dose


  The recommended quantity of a drug
• Side effect


  A secondary effect of a drug that is undesirable
• Preclinical testing


  Drug tests carried out in a laboratory on cells, tissues and live animals

  
• First stage of clinical trials


  A trial to measure the safety of a drug by testing on a sample of healthy individuals
• Second stage of clinical trials


  A trial to measure the efficacy of a drug by testing on individuals that are unwell and in need of the drug treatment
• Third stage of clinical trials


  A trial with many individuals to evaluate the overall safety and efficacy of a drug in comparison to existing drugs
• Blind trial


  A trial in which participants are unaware of whether they have received a treatment or a placebo
• Double blind trial


  A trial in which neither the experimenter nor the patient knows who is getting the research treatment to prevent bias

  
• Placebo


  A fake drug used in the testing of medication to determine the efficacy of a real drug

  
• Peer review


  The evaluation of work by several peers that are experts in a specific field

  
• Non-specific defence


  A general defence that works the same against all pathogens
• Immune system


  The cells and tissues that recognize and attack foreign substances in the body
• White blood cell


  A blood cell that fights disease

  
• Phagocytosis


  When a white blood cell called a phagocyte engulfs a pathogen to destroy it with enzymes

  
• Antibody


  A protein that binds to a specific antigen and triggers the pathogens to be destroyed

  
• Antibody production


  When a white blood cell called a lymphocyte produces antibodies
• Antitoxin


  A substance that neutralises the poisonous products of microorganisms

  
• Antimicrobial secretions


  Secretions from the skin and nose that reduce bacterial growth
• Barrier


  A physical body defence such as skin that prevents pathogens entering the body