Hello,
You have impressive qualifications, both in academics and in experience. If you write a strong personal statement about your interests and goals in pursuing a public health degree, you would almost certainly be accepted to most programs. (Only the most selective programs, such as Harvard and Johns Hopkins, tend to be very picky about applicants having a doctorate or full-time work experience before applying for their MPH degrees, but it wouldn't hurt to apply to those if they are of interest to you; your background may be sufficient.) You may want to explain how you arrived at your interest in public health and how you hope to use your biotech and/or international relations experience to your advantage (which, in international health, shouldn't be too difficult to do) just so it doesn't look like you are "degree-hopping" without a clear focus.
Funding can be more difficult to come by, since you would not be eligible for U.S. federal financial aid, but it is not impossible to find. If your visa permits you to work in the U.S., you may be able to be funded by a teaching assistantship or a research assistantship. There are sometimes also scholarships that are either not restricted to U.S. citizens or that are specificially designed for international students. Scholarships, as well as research and teaching opportunities, tend to vary by school, so it wold be wise to contact directly the schools to which you are thinking of applying. Many will have a funding/scholarships/financial aid office and/or an international student affairs office, either of which might be able to provide more specifics about funding opportunities. You might also investigate any scholarship opportunities from your own country and programs like Fulbright that provide funding for study overseas.
Good luck!
