I probably won't have the flu vaccine. I appreciate some people think this is anti-social and I am putting others at risk. I would point out that 'flu is substantially different to the other illnesses mentioned such as smallpox. They are specific and individual, the term 'flu denotes a range of illnesses which vary and in fact change from year to year. The 'flu vaccine is a scientific 'best guess' about what types of flu may be around in any one year. So you may think you are protected, but the 'flu you encounter may be a strain which wasn't in your vaccine. There appears also to be considerable confusion about colds and flu and this is understandable, the symptoms are similar, although 'flu is much worse. Both are viruses and both have variations. The reason there is no cold vaccine is because it has over 250 variations.
In my opinion it is better to know you are at risk, take precautions and act if you feel ill, than to imagine you are protected, encounter a different type, and become very ill because you didn't take it seriously