Timing of pre school booster. Urgent at 4 for immunity cover?

[FadedSapphire]

Hi,
Just some advice please. My just 4 year old has had his MMR booster and now [couple of months later] time to get other part of pre school booster.
Going on holiday most of August and don't want side affects. Would he still be covered by the last booster? Is there an urgency or would I be safe to wait a few weeks?
Thanks for bearing with me!

Tried to book appointment but due to staff shortages can't have vaccine until September. Receptionist says timing a 'guideline'.

If I were you I wouldn't be worried. Don't panic.

Thank you Crumbledwalnuts.

It's ok, it's just the diseases in dtap are so rare. Whooping cough is around, obviously but that's dangerous in infants, a 4-year-old less so. The P in dtap also doesn't protect against one of the strains of WC which was going around last winter. I hope you have a nice holiday.

No huge urgency, I'm sure DS didnt' get his until January after he started reception.

Thanks both of you.
Holiday overseas staying with inlaws that expect me to be a Stepford wife...
If we all survive [with no major fall outs] I will consider the holiday a success!