timing myxi jabs - advice please

eric has his first ever myxi jab on 26th feb 09 and his second on 9th september 09.

i'm unsure as to when to book his next one for - would you leave it til march or bring it forward a couple of weeks? how long after the jab is it properly effective and when does the wretched disease start to peak?

I got a postcard through as a reminder from the vets to book them in...think it was Myxi

ETA..March sounds about right ...Bella and Oscar had there's Nov so due in May

thanks. i was just worried in case it was best not to leave it the full 6 months