Daughter DOESN'T need 4th Dtap vaccine?

So I found an old topic regarding this but it wasn't fully answered.

I am scheduled for the MenC/HIB vaccine for my 15 month old at the surgery here in Taunton. My daughter is, according to my US schedule, due for her 4th and last Dtap vaccine as well. When I told this to the Child Health Board, they told me that in the UK the 4th dose is done much later.

So...is this really OK? I know I should trust my health care provider but all the US sites are saying DON'T MISS THE FOURTH DOSE IT'S VERY IMPORTANT!

However, the Health Protection Agency does state "Individuals coming to UK part way through their immunisation schedule should be transferred onto the UK schedule and immunised as appropriate for age." So there's that. But my brain still says "the disease doesn't know if my child is in the US or UK."

Am I worrying a lot over nothing? Thoughts?

It might be that the level of disease on this instance is lower here.  The US has never vaccinated against TB for instance.

But I would ask about paying for it privately.  Pertussis has become an increasing issue across the world and maybe the UK hasn't caught up to this thinking yet.

You can still get whooping cough (pertussis) even after all the jabs. It would be milder of course. The immunity does wear off, which is why they will top you up every 10 years for tetanus, etc.
When I asked for the mumps vaccine for my kids I was told the NHS didn't offer it and they wouldn't do it even if I paid for it. (My son later contracted mumps and subsequent viral meningitis) This was a long while ago, so I hope they have changed their policy since then.

They are definitely open to mumps vaccines now, as a trip to Sri Lanka last year revealed that DH had never had his jabs (mum had delayed it for some reason, then he got very ill with mono, and then never really needed to go to the doctor again, and they never actually transferred his records till we asked recently, so no one knew?). He got shots for EVERYTHING and definitely got the equivalent of an MMR. 
I've been told by a few nurse-friends that pertussis is on the rise and it would be wise for both of us to get a DTAP booster, especially if we are going to try and conceive soon. That said, both of them did mention that it's the US that has had the stronger uptick in infections, so not necessarily a standard recc for the UK yet.