Your body needs about 2 weeks after receiving the flu vaccine to build up antibodies. This year's vaccine is only about 62% effective, which means you can still get the flu if you're exposed to one of the strains that isn't in the vaccine. Also, I've heard that some people can still develop a case of flu, even from one of the strains in the vaccine, but the case will be much milder than if they didn't have the vaccine. Lastly, it's pretty much just not true that the vaccine causes flu cases. It's purely coincidental if someone gets sick with flu within a few days of getting immunized.
I wouldnt risk it. The worst flu this year is flu strain B and the flu shot does not cover that one. It was a surprise this year. Also the flu shot is only 67% effective period so you can still get sick even with the shot.
Quite simply no. Full benefit from the vaccine occurs 4-6 weeks after receiving it. Also, 62 percent efficient vaccine is remarkable for flu vaccine. Comments like "Only 62 percent effective" are most likely made by non-health professionals. That is the most efficient vaccine from CDC to date. GET VACCINATED.