Is Vamp immortal

*SPOILER ALERT*
No. Vamp's body is riddled with advanced nanomachines that allow him to quickly recover from wounds and injuries that would be fatal to a normal person. The reason for this superhuman ability is not made clear until Act 4 (Shadow Moses) of MGS 4: Guns of the Patriots. Vamp is killed by Naomi Hunter by neutralizing his nanobots with the syringe after he is fatally wounded and hadn't had the time to recover after a fight with Cyborg Ninja Raiden in the same room that Snake fights REX in MGS 1.