For info of all concerned, may I make you aware of the information that follows, that has just come out in the HSF newsletter today 27th October 2014. Hope it helps.
"This is a question we are asked many times during the
winter months so ... if you have primary APS/Hughes
syndrome then, yes, it is considered safe and effective
for you to have the flu jab. However, if you are taking
warfarin it is important to monitor your INR a day or two
after having the vaccine, as it has been reported that
your INR can increase slightly."