What if the immune system of someone isn’t up to scratch?

Question: What if the immune system of someone isn't up to scratch?
- Keywords:
  weak immune system
Asked by Peter to Carmen, Daniel, Laura, Noel, Steph on 11 Mar 2015.
- Carmen Denman answered on 11 Mar 2015:
  
  Hi Peter,
  
  Then they would probably get sick quite often! And could try to improve their immune systems by living healthfully, and looking into vaccinations and other ways of ‘boosting’ immunity.
  
  Cheers,
  Carmen

Question: What if the immune system of someone isn't up to scratch?