Modifiers matching antigen:

• foreign,
• lethal,
• exogenous,
• proteinaceous,
• viral,
• several,
• main,
• endogenous,
• harmless,
• active,
• strong,
• environmental,
• extraneous,
• noninfectious,
• extrinsic,
• microbial,
• innocuous,
• small,
• particulate,
• internal,
• diverse,
• infectious,
• nutritional,
• harmful,
• free,
• outdoor,
• outside,
• dangerous,
• peripheral,
• bacterial,
• soluble,
• perennial,
• oral,
• single,
• possible,
• indoor,
• simple,

Simple categories matching lethal:

• disease,
• weapon,
• injury,
• treatment,
• cause,
• infection,
• organism,
• accident,
• vehicle,
• means,
• device,
• pathogen,
• thing,
• object,
• devices,
• condition,
• antigen,
• substance,
• chemical,
• animal,
• round,
• drug,
• danger,
• trap,
• agent,
• bacteria,
• disorder,
• munition,
• process,
• microbe,
• event,
• item,
• virus,
• equipment,
• instrument,
• defect,
• microorganism,
• cancer,
• stress,
• molecule,
• affliction,
• nature,
• neoplasm,
• anomaly,
• tumor,
• illness,
• property,
• malignancy,
• abnormality,
• gene,
• medication,
• complication,
• medicine,