Trivalent Human Papillomavirus (HPV) VLP vaccine covering HPV type 58 can elicit high level of humoral immunity but also induce immune interference among component types

Both Human Papillomavirus (HPV) type 16/18 bivalent vaccine and type 16/18/6/11 quadrivalent vaccine have been proved to be safe and effective, and licensed for public use. However, these two vaccines do not quite match the distribution of HPV types in China, Southeast Asia and Latin America, where HPV 58 is highly prevalent. Here we produced three types of virus-like particles (VLPs) in baculovirus expression system, formulated a trivalent vaccine containing HPV 16, 18, and 58 L1 VLPs and examined its in vitro neutralizing titers This vaccine could induce high level and long-term humoral immunity against the component types. But immune interference was observed when comparing type specific neutralizing antibody levels induced by trivalent vaccine to those by corresponding monovalent vaccines. This kind of interference would become more obvious when formulating more types of VLPs into multivalent vaccines, but could be greatly overcome by decreasing the antigen dosage and adding a proper adjuvant. (C) 2010 Elsevier Ltd All rights reserved