This study looks at whether drinking pasteurized milk (milk that has been heated to kill germs) with inactive particles of the flu virus H5N1 could be detected in the nose or throat. The inactive virus cannot cause disease. **CDC** (Centers for Disease Control and Prevention) wants to understand if milk affects flu tracking. **Participants** will drink 250 mL of milk during one or three visits. They will have nasal and throat swabs taken right after drinking the milk. Some will also give blood, saliva, and stool samples at the start and 21-30 days later.

• Study involves 1 or 3 visits, with some follow-up samples after 21-30 days.
• Participants must be healthy adults aged 18-64.
• Participants cannot have recent illness, take certain medications, or have certain health conditions.