As Terran
Make:
Ghost
Viking
MarineSnipe and focus fire Vipers before Abducts start.
Open in the counter tool with Viper tagged ->As Protoss
Make:
High Templar
Stalker
TempestFeedback is the cleanest answer if Templar are protected.
Open in the counter tool with Viper tagged ->As Zerg
Make:
Infestor
Hydralisk
CorruptorFungal Vipers before the spellcaster trade begins.
Open in the counter tool with Viper tagged ->
Zergling
Baneling
Roach
Ravager
Queen
Lurker
Mutalisk
Overlord