MMR Booster - what age?

[SuperSaint]

DD is now 3.2 and had the MMR when she was 13 months old. Around here the booster is given between 4 and a half and 5 years old so she has another 18 mths to wait.
There have been incidents of mumps and measles at her nursery recently, including some children who have had the 1st MMR. I spoke to the practice nurse at the Health centre today and she said that children have some immunity after the first injections but not full immunity until after the booster. She said I can arrange for DD to have the booster earlier if I want.
Is 4 or 5 the usual age for the booster or has anyone had it done earlier? Is there any reason to wait another 18mths? I am thinking I may as well have it now so she has full immunity ASAP?
I'd welcome any comments on this.
Thanks in advance.

I'm in the same boat, Saint.

Am also thinking of having DD1's booster earlier, as she, too, has only had the one at 13 months, is entering nursery next month and has a 7-month-old baby sister - too young for the jab.

dd had hers the week after her 4th birthday. I thought they tried to give the booster before they started school.

DD is 4y3m adnd has just had all her pre school boosters, including the MMR.

I thought the booster was a catch-all for the minority for whom it didn't "take" first time around, not a top up. dd had hers at 18 months which was normal where we were then living. ds was about 4 iirc.

My dd had the single vax but I'm wondering whether to go ahead with the MMR booster now anyway. The private clinic recommends single booster shots 18mths after the originals - they would though wouldn't they ££££££££££

The second jab is given as not all children get immunity from the first one. From MMR the facts website:

Why are children given two doses of MMR?

To give better protection.

After the first dose, between 5% and 10% of children are not protected against the diseases. After two doses of MMR, less than 1% are left unprotected.

For this reason, all countries in the European Union and the US, Canada, Australia and New Zealand recommend two doses of MMR.

Thanks for the replies. On NHS direct it says that the booster is given between the ages of 3 and 5 but it is interesting to see that most children don't have it until they are 4.

Seona - that's good to know. it means DD is likely to be protected already but there's always the worry she'll be one of the 5 or 10% who are not.

I'm still no closer to a decision!