Antitoxin

6 clues
Germ fighter
Immunity offerer
Type of neutralizer
Neutralizer of a sort
Bacteriologist's discovery
It could be your shot in the arm
Similar answers:
Aanti
Adamantine
Adamantium
Andantino
Antarcticalaskantigua
Anti
Antiabortion
Antiacid
Antiacids
Antiaging
Antiam
Antiamerican
Antianti
Antiar
Antiarab
Antiart
Antibes
Antibesauntie
Antibias
Antibiotic