there is still some viral shedding sometimes during the scab stage but it's much lower than before the scab stage. as mistakeguy already said, we recommend waiting until the scab has fallen off before resuming kissing/oral sex if your partner is negative.
http://www.ashastd.org/herpes/herpes_learn_oralherpes.cfm is a terrific link for more info on oral herpes.
grace
You should always refrain from kissing until the skin has completely healed.