A .22 would be about the same as a hold-out or a light pistol. Which, at 4P is more dangerous than the average (2 to 3) person with a knife (STR/2+1)P.
Since you can only dodge a bullet with full defense, the answer in SR4 terms is you'd always rather face the guy with a knife. And while firefights in SR4 may take place at longer range, that doesn't mean that the mechanics should inherently make melee significantly weaker than ranged combat. If anything, it should make melee stronger in order to justify anyone ever making the made dash to close into melee range.
As it stands, if I'm shooting you from 1 meter away (simple action), I get +2 for shooting "point blank", and you avoid the attack with flat Reaction unless you spend a complex action (as an interrupt) to add your dodge skill to the pool. Base damage of 4P (assume a light pistol). Then, I get to shoot you again (at a -1 for recoil, assuming no recoil compensation), and you dodge with flat Reaction -1 (unless you already spent or choose to spend a complex action as above for Full Defense).
Reverse the situation. You're attacking me with your knife (a complex action). You get no bonus for Reach, in spite of the fact that I'm not wielding a melee weapon. I, without spending any actions, get to dodge with Reaction + Dodge (or Gymnastics, or Parry with Unarmed, whatever I happen to be best at). Since it was a complex action to stab at me, you don't get to stab at me again.
In Shadowrun, I'll always choose to face the guy with a knife, all else being equal.