3.1.7 Vaccination

• What does a vaccine contain?

  Small quantities of dead, weakened, or inactive forms of a pathogen.
• Can vaccines be made against both bacterial and viral diseases?

  Yes.
• True or false? By the time we're adults we've already been vaccinated against multiple diseases.

  True.
• How do vaccines work?

  They expose us to the antigens of a pathogen so that we can develop immunity to it.
• What is the benefit of widespread vaccination?

  Widespread vaccination campaigns can prevent outbreaks of disease (epidemics). This is because 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. We sometimes call this herd immunity.
• What are the potential drawbacks of vaccines?

  They can cause mild symptoms such as fever or a sore arm, they can (in rare cases) cause severe reactions such as seizures and they don't always give full immunity to the disease.
• What takes a few days to learn how to deal with a new pathogen?

  White blood cells.
• What does the MMR vaccine contain?

  Weakened pathogens of measles, mumps, and rubella.
• What can white blood cells do after vaccination?

  Mass-produce antibodies to kill the pathogen.
• Does smallpox still occur?

  No.
• What percentage have polio infections fallen by?

  99%.
• Who was the first to discover the vaccine?

  Edward Jenner.