how effective are vaccination programmes

• how are pathogens that exhibit no or low levels of antigenic variation treated


  by a single round of immunisations
• why are pathogens that have many antigenic types hard to treat


  because they mutate more frequently
• how are pathogens that mutate frequently treated


  repeated immunisation
• give an example of a pathogen with high mutation rates


  influenza
• what type of people are offered flu vaccinations from the NHS


  older immunocompromised and asthmatic people
• how often are flu vaccinations


  annually
• what is meant by herd immunity


  if enough people in a population are vaccinated the spread of the disease is controlled
• why might some people choose to not have vaccinations

  religious beliefs preference mistrust a pharmaceuticals or safety fears