Active immunity

  • result of infection/naturally/artificially/vaccination
  • body manufactures its own antibodies
  • stimulated by memory cells
  • most effective/rapid response (second infection) persists for a long time


Passive immunity

  • antibodies from another individual
  • give immediate protection
  • protects for short time (about a week)



  • natural active
  • natural infection by pathogen/antigen
  • natural passive
  • antibodies from mother to foetus/across placenta
  • antibodies in colostrums/breast milk to baby



  • artificial active
  • injection of pathogens/antigens into the body
  • artificial passive
  • ready-made antibodies injected into the body


How vaccination give protection against diseases

  • vaccination- injection/administration of an antigen
  • causes production of antibodies (against the antigen)
  • vaccination is artificial immunity
  • booster injection may be used for longer lasting/more effective protection
  • response due to B and T cells memory cells survive for a long period
  • memory cells are B cells
  • memory cells enable a rapid response
  • antibody brings about destruction of antigen/organism carrying it
  • effective against infectious diseases 9e.g. small pox/diphtheria/polio/measles/whooping cough) – vaccinate children in national/international campaigns


Describe why vaccination managed to eradicate small pox but not malaria

Small pox

  • varilosa virus stable
  • (harmless) strain of (live) vaccine effective
  • vaccine could be kept for a long time (6 months)
  • infected people were easy to identify
  • ring vaccination was possible
  • political stability during that time



  • no vaccine/no effective vaccine against the protozoan
  • resistance of Plasmodium to drugs
  • resistance of vector/mosquitoes to DDT/dieldrin/insecticide
  • difficulty of mosquito control
  • expensive to expand the programs.
  • civil wars disrupt the programs.


  • caused by an RNA virus
  • viruses are intracellular pathogens
  • antigenic concealment have a short time in the blood
  • major changes in the epilate as a result of mutation
  • poor response to vaccine (children do not respond well to one dose of vaccine)
  • deficiency immune system
  • or protein energy malnutrition
  • need several boosters which are expensive
  • high birth rates and flighting populations make it difficult for boosters
  • follow up cases and trace contacts also impossible
  • refugees and immigrants from reservoirs of the infection
  • it is highly infectious resulting in the whole population requiring vaccination which is highly expensive
  • the virus is of hiring attenuated virus can be virulent



  • some strains of TB bacteria resistant to drugs;
  • the AIDS pandemic;
  • poor housing and rising homelessness in inner cities in the developed world;
  • the breakdown of TB control programes particularly in the USA;
  • partial treatment for TB increases the chance of drug resistance in Mycobacterium;
  • attacks many of the poorest and socially disadvantaged because it is spread by airborne droplets;
  • so people who are overcrowded are particularly at risk;
  • those with low immunity particularly because of malnutrition or being HVI+ are also vulnerable;
  • transmission is easily achieved but the bacteria may remain in the lung, or in the lymphoid tissue for years until they become active;




  • cholerae in intestine;
  • out of reach of immune system;
  • antigenic concealment;
  • antibodies broken down in intestine;
  • antibodies are proteins;
  • ref to pH and effect on structure or shape; e.g. in the stomach
  • denaturation;
  • vaccine stimulates antibodies in, blood / lymph;
  • not in gut;
  • oral vaccine needed;
  • mutation;
  • different strain idea;
  • AVP; e.g. not required in developed countries
  • developing countries cannot afford to develop vaccines
  • no / limited, demand
  • cholera can be treated with ORT
  • can be treated with antibiotics

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