I think it’s important to have a brief background on the person so my first question would be about their education and work experience.
What is your educational and work background?
This could lead to other questions about why they choice this field and the things that interested them to choice this career path.
What made you interested in health communication?
I could then change this around to cater to their specific jobs whether they are a public relations professional for a hospital or a representative for a pharmaceutical company. After this I would explore the usefulness in communication in their field.
How is communication important for your profession?
Finally I would ask a two-part question. First;
What is your overall title and responsibilities?
What does your typical workday entail?
This will give a good macro and micro look at their professional responsibilities. Having an overview of the profession is important to help you start to understand what they do. What type of responsibilities do they have within the company is needed to understand a profession. The day to day question will help have a much more real look at what this person actually does. What is it like to work at this company and have this job? All companies are different and while someone might have the same responsibilities as someone else at a different company, their actual workday can be very different.