1. Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
2. Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, School of PharmacyVirginia Commonwealth University, Richmond, VA 23298, USA
3. Department of Nanomedicine and Biopharmaceuticals, National Engineering Research Center for NanomedicineHuazhong University of Science and Technology, Wuhan, Hubei 430074, China