Possible Clues:

• Most see alcoholic drink as potential shot in the arm?
• It may lead to the truth
• That finishes with a drink in the blood
• That's the bloody amoung around 'er
• Just one bloody drink at last!
• Intravenous injection
• Blood component containing antibodies, used in immunisation
• Inoculated fluid
• E's back on the bloody drink
• Problem keeping emergency room's vaccine