Conventional and well-established guidelines for the ethical conduct of clinical research are necessary but not sufficient for addressing research dilemmas related to public health research. There is a particular need for a public health ethics framework when, in the face of an epidemic, research is urgently needed to promote the common good. While there is limited experience in the use of a public health ethics framework, the value and potential of such an approach is increasingly being appreciated. Here we use (...) two examples of adolescent women as potential candidates for participation in microbicide trials to illustrate how ethical decisions for public health research can be enhanced by drawing on both traditional research ethics guidance, and the emerging framework for public health ethics. (shrink)