Normally flu vaccine is given around the month of October because that's the typical start of flu season, so the longer you delay getting the vaccine, the more chances are that more people will contract influenza.
Yes, there's always concern when we have delays, whether it's in production or whether it's in determining what's going to be the mix that needs to go into the vaccine. What it really tells us, though, is that we're going to have to be a little more vigilant about washing our hands and doing all of the public health measures until we can all get our flu shots in November.