In your opinion, of all the vaccines in the world which one is it the most important, why?

Question: In your opinion, of all the vaccines in the world which one is it the most important, why?
- Keywords:
  opinion,
  vaccine
Asked by Anjalo to Carmen, Daniel, Laura, Noel, Steph on 10 Mar 2015.
- Carmen Denman answered on 10 Mar 2015:
  
  Hello,
  
  I couldn’t choose! Smallpox, Polio would be my top two because of their control of such hugely devastating disease and also how well they work. Smallpox is the ONLY disease we humans have officially been able to eradicate. Polio is almost there but still a few cases a year.
  
  Cheers,
  
  Carmen
- Laura Garcia Ibanez answered on 10 Mar 2015:
  
  Hi Anjalo! I totally agree with Carmen. The eradication of Smallpox thanks to vaccines was a huge step. I really hope this can be done again with many more diseases. Cheers!
- Noel Carter answered on 10 Mar 2015:
  
  I would also agree with everyone. Smallpox was an awful disease and it’s eradication shows what is possible with vaccination. I think people have forgotten and so uptake of vaccines are dropping and outbreaks of things like measles are on the increase. I think people have forgotten how devastating measles can be for a small minority of people who contract it.

Question: In your opinion, of all the vaccines in the world which one is it the most important, why?