My DS was bullied relentlessly at school for many years due to standing out from the others becaise of Aspergers.
I was also ringing the school on a daily basis, having meetings about it with teachers and writing letters to the Head.
You won't like what I am about to say - It won't get better and will probably get worse when they get to senior school and the differences as a result of Aspergers become even more apparent to their peers.
I used to write to school naming names of the children who bullied him. At times it seemed the whole class were bullying him - which is a difficult concept as 'tradirionally' it's one bully against one victim but DS was telling the truth and the whole class had actually turned against him and was acting in a disgustingly anti-social way towards him. That's something to bear in mind.
Within a junior school with 'class teachers' for the majority of the day and a small community of pupils steps can and should be taken by school to stamp this out, however once the child is at secondary school with a whole new set of classmates and children who had attended other junior schools and with different teachers for each lesson so continuity is lost - that's when problems really escalate.
I was told that school couldn't protect DS throughout the school day. as a result he was subjected to serious physical assault on several occasions - noe of which were adrquately investigated or dealt with by school. I even called in the Police following one incident which necessitated Ds having to attend A&E. Still school maintained it was 'perceived' rather than 'actual' bullying and did nothing. At that point I removed him from school.
The best thing you can do is to apply for a Statement immediately. Don't wait, as school will be telling you to do, until school have gathered all the evidence to support an application for an assessment for a Statement - apply yourself directly to the LA. the school will be given time to get their evidence then. You can't allow school to drag their heels over an application as your child is 9 and almost at the point of transition to senior school. It's a lot easier to get a Statement while in junior school than it would be in secondary school with this lack of continuity of teaching staff.
A Statement will ensure that measures are in place for his/her transition to secondary school and they will not be left to struggle on on their own.
Bullying - I hate this word - is assualt. If it happened outside school the Police would be involved - but unfortunately because these incidents happen in school they are played down as bullying.
Don't underestimate the effect these assaults have on the victim. My son spent 6 months in a CAMHS pyschiatric unit as a result of the abuse and criminality he was subjected to in school, and is still under pyschiatric care 8 years later.
My advice - complain, complain complain to school and to the LA and apply for an assessment for a Statement immediately, yourself.
Best wishes