Possible Clues:

• Agent in accommodation concerns immunologist
• Inclined to withhold information, maybe, for component of medicine?
• ... against information on what delivers immunity
• Opposing knowledge that could help fight infection
• Toxin, an element feasting on skin of grape
• Toxin perhaps in plant I generally cut down
• Foreign invader, colonist with current information
• Trigger for immune response
• Argentina -- upset without a right means of defence
• It induces an immune response