Uh huh. So how are you going to avoid getting the flu? Or for that matter, virtually any respiratory virus for which a vaccine is lacking?
The question to which I was responding was a general one, and didn't pertain specifically to influenza. Now, on to your question...
Vaccines do exist for the flu, it's just that they are not completely protective because the virus easily mutates, and thus there are many different strains circulating each year. Only those that are expected to be the most prevalent strains for a particular season can be placed in the vaccine.
Now even if there is absolutely no vaccine for a particular respiratory virus (such as in the case of SARS), protective measures can be taken. There is a reason many folks in areas affected by SARS were wearing hospital masks during the height of the scare. If you don't inhale any infected aerosols, then you won't become infected with the organism.
All measures aside, there is no way to guarantee 100% that a person will be able to avoid contracting a particular disease, simply because that would require testing an infinite number of possibilities. New methods of transmission may develop, and breakdowns in public health measures do occur. I get the impression that you want to be told "Do this, and you can't get sick with this bug, no matter what." That expectation will only lead to your frustration.