Possible Clues:

• Get in a fantastic new biological substance
• Something inducing an immune response, neat gin (anag.)
• Biological substance extractable from gentian
• Dope found on colonist, one that's given immunity
• From plant I generate toxin
• One might gain ten from such a toxin
• A or B in blood typing, e.g.
• … turn finally on eating? It'll help to get antibodies
• Opposing dope that could help towards fighting infection
• Immune response cause