first kill him but then get your synge{wrong spelling i think}and open your weapon
bar{where u change your weapons]and put none {FAST}before he gets up.you go right in front
of him press L1 and press triangle fast before he breaks out of the CQC[which is the move
that your suppose to do} and then hes killed done.its a piece of cake

cody09 is half right but what you do is equip the syringe and a weapon then after you
deplete his life unequip your weapon and he will stand and his health will start coming
back,now press R1,not L1 to do a cqc move then press triangle and he will be dead

CALL BUFFY THE VAMPIRE SLAYER, ANGEL, HELL MAYBE EVEN BLADE...THIS GUY IS TOUGH

i would agree with the second unregisterd person

Thanks for your advise...I defeated him (barely) three times in one battle...hopefully now
I can finish him off...Good looking out, Thanks

ok i press r1 and all it dose is knock him don to the ground how am i suppose to hold him
and give him cqc ???

You must stand behind vamp to grab him then you can inject him.