Think this is why so many people say they get sick after flu shots - because flu shots decrease your immunity to other things kicking around (hypothesis)?
"Canadian researchers noticed in the early weeks of the pandemic that people who got a flu shot for the 2008-2009 winter seemed to be more likely to get infected with the pandemic virus than people who hadn’t received a flu shot.
Five studies done in several provinces showed the same puzzling and unsettling results. "
Not sure whether this was a one-off, researchers decided to recreate the issue using ferrets.
"...worked with 32 ferrets, giving half the 2008 seasonal flu shot and the remainder a placebo injection. The work was blinded... Later, all the ferrets were infected with the pandemic H1N1 virus.
The ferrets in the vaccine group became significantly sicker than the other animals, though all recovered."