You might feel much worse if you didn't get the flu vaccine. The flu vaccine
had good protection against two strains of the influenza going around and
seemed to protect against serious illness against the third.

In fact, if you had mild flu-like symptoms, you might have had a very mild
case of the flu, which would have been more severe or even deadly had you
not had the flu vaccine.

I really doubt that symptoms that started about 3 weeks after you got the
flu shot were related to the vaccine. The vaccine is mostly protein that is
like the protein that is found on the flu bugs that were going around last
spring. Your body makes antibodies to the proteins, so that you are much
less likely to get influenza from those flu bugs. In addition, the shot does
not contain any live virus.

The nasal vaccine does contain live virus. It causes what is essentially an
extremely mild infection. However, within a week or two, you should have
recovered from any ill effects of the vaccine. I really doubt they would
show up after that time.

What I think happened is that around Christmas, you got a new infection.
Perhaps a virus or even a mild case of the flu. This would have happened
even if you didn't get the vaccine (in fact, it might have been much worse
if you did get the vaccine). It also sounds like you have sinusitis. The
nasal drainage from this might be causing your cough. However, I doubt very
much that these are from the vaccine.

Hope you feel better soon.

Jeff