The problem is most likely in the interaction's own raws. Need to see them to be sure.
This is the one that actually gives you the interaction:
[INTERACTION:ORIGINAL_VAMPIRE_1]
[I_SOURCE:DEITY]
[IS_USAGE_HINT:MAJOR_CURSE]
[IS_HIST_STRING_1: cursed ]
[IS_HIST_STRING_2: to prowl the night in search of blood]
[I_TARGET:A:CREATURE]
[IT_LOCATION:CONTEXT_CREATURE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:WERECURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:VAMPCURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:DISTURBANCE_CURSE]
[I_EFFECT:ADD_SYNDROME]
[IE_TARGET:A]
[IE_IMMEDIATE]
[IE_ARENA_NAME:Vampire (Original)]
[SYNDROME]
[SYN_CLASS:VAMPCURSE]
[CE_ADD_TAG:LOCKPICKER:BLOODSUCKER:NO_AGING:STERILE:NOT_LIVING:NOEXERT:NOPAIN:NOBREATHE:NOSTUN:NONAUSEA:NO_DIZZINESS:NO_FEVERS:PARALYZEIMMUNE:NO_EAT:NO_DRINK:NO_SLEEP:NO_PHYS_ATT_GAIN:NO_PHYS_ATT_RUST:START:0]
[CE_PHYS_ATT_CHANGE:STRENGTH:200:0:AGILITY:350:0:TOUGHNESS:350:RECUPERATION:350:0:START:0]
[CE_MATERIAL_FORCE_MULTIPLIER:MAT_MULT:NONE:NONE:1:2]
[CE_BODY_MAT_INTERACTION:MAT_TOKEN:RESERVED_BLOOD:START:0]
[CE:INTERACTION:VAMPIRISM]
[CE:SYNDROME_TAG:SYN_INGESTED]
[CE:SYNDROME_TAG:SYN_INJECTED]
[CE:SYNDROME_TAG:SYN_INHALED]
[CE_DISPLAY_TILE:TILE:165:4:0:0:START:0:CAN_BE_HIDDEN]
[CE_DISPLAY_NAME:NAME:vampire:vampires:vampiric:START:0:CAN_BE_HIDDEN]
[CE_BP_APPEARANCE_MODIFIER:START:0:BP:BY_CATEGORY:TOOTH:APPEARANCE_MODIFIER:LENGTH:150]
[CE:COUNTER_TRIGGER:DRINKING_BLOOD:1:NONE:REQUIRED]
[CE_SENSE_CREATURE_CLASS:START:0:CLASS:GENERAL_POISON:15:4:0:1]
[CE_CAN_DO_INTERACTION:START:0]
[CDI:ADV_NAME:Hypersonic screech]
[CDI:INTERACTION:VAMP_SCREAM]
[CDI:TARGET:A:LINE_OF_SIGHT]
[USAGE_HINT:ATTACK]
[CDI:TARGET_RANGE:A:10]
[CDI:WAIT_PERIOD:20]
[CDI:VERB:screech:screeches:NA]
[CDI:TARGET_VERB:wobble:wobbles]
[CE_CAN_DO_INTERACTION:START:0]
[CDI:ADV_NAME:Convert]
[CDI:INTERACTION:VAMPIRISM]
[CDI:TARGET:A:TOUCHABLE]
[CDI:WAIT_PERIOD:280]
[CDI:VERB:bite:bites:NA]
[CDI:TARGET_VERB:pale:pales]
And this is the one that is supposed to be used on the target:
[INTERACTION:VAMPIRISM]
[I_SOURCE:INGESTION]
[IS_HIST_STRING_1: consumed the tainted blood of ]
[IS_HIST_STRING_2: and was cursed]
[I_TARGET:A:CREATURE]
[IT_LOCATION:CONTEXT_CREATURE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:WERECURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:VAMPCURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:DISTURBANCE_CURSE]
[I_EFFECT:ADD_SYNDROME]
[IE_TARGET:A]
[IE_IMMEDIATE]
[IE_ARENA_NAME:Vampire 2.0]
[SYNDROME]
[SYN_CLASS:VAMPCURSE]
[CE_ADD_TAG:BLOODSUCKER:NO_AGING:STERILE:NOT_LIVING:NOEXERT:NOPAIN:NOBREATHE:NOSTUN:NONAUSEA:NO_DIZZINESS:NO_FEVERS:PARALYZEIMMUNE:NO_EAT:NO_DRINK:NO_SLEEP:NO_PHYS_ATT_GAIN:NO_PHYS_ATT_RUST:START:0]
[CE_PHYS_ATT_CHANGE:STRENGTH:200:0:AGILITY:300:0:TOUGHNESS:300:RECUPERATION:350:0:START:0]
[CE_MATERIAL_FORCE_MULTIPLIER:MAT_MULT:NONE:NONE:1:2]
[CE_BODY_MAT_INTERACTION:MAT_TOKEN:RESERVED_BLOOD:START:0]
[CE:INTERACTION:VAMPIRISM]
[CE:SYNDROME_TAG:SYN_INGESTED]
[CE:SYNDROME_TAG:SYN_INJECTED]
[CE_DISPLAY_TILE:TILE:165:4:0:0:START:0:CAN_BE_HIDDEN]
[CE_DISPLAY_NAME:NAME:vampire:vampires:vampiric:START:0:CAN_BE_HIDDEN]
[CE_BP_APPEARANCE_MODIFIER:START:0:BP:BY_CATEGORY:TOOTH:APPEARANCE_MODIFIER:LENGTH:150]
[CE:COUNTER_TRIGGER:DRINKING_BLOOD:1:NONE:REQUIRED]
[CE_SENSE_CREATURE_CLASS:START:0:CLASS:GENERAL_POISON:15:4:0:1]