The Glock 17 is the first weapon in quarantine you get, because you get it when you first join, accompanied with 2 stacks of 9mm ammo. (1600 rounds) It may be the weakest pistol, coming in at only 18 damage. Correct me if I'm wrong.
Along with the Glock and 9mm ammo, you also get a pocket knife.
It is effective against tier 1 zombies and all that, but once you get a newer pistol/gun [Example:Uzi], DITCH IT IMMEDIATELY.
So, thats all.