Berkeley and UCLA will be a stretch, but are possible. In addition to getting your numbers up as much as possible, I think you should concentrate on telling a story with your personal insight answers (essays) that says why you are interested in public health, how your background has prepared you, and make sure you include that this undergraduate major is offered at only a few select institutions including UCB, UCLA, and UCI–and you will make it clear that you are a perfect fit for these programs, and that is why they should let you in. You also might still have time to craft something that shows your commitment to the field–an internship, a project of your own design, maybe talking to someone in the public health dept at UCI to see if you can have some role (even if it’s data entry) on a study–that commitment and clarity of purpose might push you over the top. Disclaimer: I have no inside knowledge on UC admissions.