I have COPD, asthma and allergies and prior to getting the pneumococcol vaccine, when I would get a cold, it would quickly turn into pneumonia or bronchitis. After getting the vaccine, my colds are just colds now. It is a one-time only vaccine that is to prevent secondary bacterial infections and in my case, it works. I also get the flu vaccine every year as every year it is different and I've never had a bad reaction to it. With so many varieties of flu out there, I am hedging my bets that having all these other flu vaccines in me may prevent me from succumbing to the worst varieties.
But think about a world without electricity, refrigeration, possibly a whole lot of dead bodies and the possibilities for disease becomes endless. If there is a vaccine that you can get, you'd be wise to CYA now.