Department of Medical Oncology , the First Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an 710061, China;
Medical Laboratory Center of the First Affiliated Hospital of Medical School, Xi'an Jiaotong University , Xi'an 710061, China;
Institute for Cancer Research, School of Life Science & Technology, Xi'an Jiaotong University, Xi'an 710061, China;
Institute for Cancer Research, School of Life Science & Technology, Xi'an Jiaotong University, Xi'an 710061, China;
Institute for Cancer Research, School of Life Science & Technology, Xi'an Jiaotong University, Xi'an 710061, China;
human papilomavirus type 18; DNA vaccine; site-directed mutation; humoral immunity; cellularimmunity;