You've obviously never had a vaccine in your life,
Not during the last 60 years. That's probably why I don't get 'flu or other viruses/sickness. I don't take any pharma medication either, and that includes anti-biotics, antacids or pain killers. I do drink coffee and quality alcohol, although I have cut down on the alcohol as I spend so much time in the van.
Smoking Pot?
Getting a vaccination is a requirement to travel to certain parts of the world to prevent contracting virus' already present in that region. Certain countries or even airlines and cruise liners might require you to be inoculated prior to travel and the proof is in the documents you have (such as the Vaccine Certificate Booklet I mentioned earlier).
Will a vaccine prevent further outbreaks? It already has for virus' such as Polio, Small Pox and similar. If you're sixty, then you would have heard of the Polio Vaccinations when you were quite young.