How to Beat Vamp!

So on my third try, I finally got it. How does one beat Vamp in Metal Gear Solid 4: Guns of the Patriots. Easy. Use the syringe! Get him in CQC (I used the knife.) But first I got all his health and psych down to the last sliver, then worked on the Syringe. After that, you fight gecko’s and after the last self-destruct one is destroyed, Raiden kills vamp. It was one of the worst boss battles I’ve ever faced.

[EDIT]

Equipped Rations + A4 / P90 / M60 / Tranq Gun / Shock Knife. This is how I beat him, get both Vamp’s LIFE and PSYCH down to the last sliver (not killing him, just so the meter is very very small). Of course you have to dodge those damn knives, I usually run around in the rubble when he does that. Once you have Vamps meters down you have to inject the syringe. Equip the Syringe + Shock knife. Get in the lift where you begin. Run around rolling and evading (L1 + X + “Left Stick Direction” works good). When you get the chance behind his back, you have to CQC him with R1 (don’t throw him down). Get him in the head lock and then the Icon will pop up (Triangle To Syringe). Snake’ll inject Vamp and that parts done!

The next part is to take out the GEKKOs with the Rail Gun. Shoot the ones with red lights. They’ll Self Destruct if you don’t and you’ll lose. Kill the others if they get to close. Once the last one is destroyed, it’ll cutscene. Don.