Background/Objectives: Virus-like particle (VLP) vaccines based on human papillomavirus (HPV) L1 proteins have high efficacy for preventing cervical cancer and other HPV-associated diseases. The production yields of commercial HPV VLPs remain suboptimal. We aimed to improve HPV VLP production efficiency using a hyper-expression vector system for the expression of L1 proteins of four major HPV serotypes—HPV 6, 11, 16, and 18. Methods: HPV L1 proteins were expressed in Trichoplusia ni (Hi5) insect cells via a hyper-expression baculovirus vector system. Following cell lysis using a microfluidizer, VLPs were purified through a two-step chromatographic process. Particle morphology was characterized using transmission electron microscopy and dynamic light scattering. Immunogenicity was evaluated using a murine model; mice received three intramuscular injections of the purified quadrivalent VLPs. The resulting IgG and neutralizing antibody responses were compared with those elicited by the commercial quadrivalent vaccine, Gardasil. Results: The L1 proteins from HPV 6, 11, 16, and 18 were successfully expressed at high levels in Hi5 cells, forming uniformly sized VLPs with hydrodynamic diameters of 50–60 nm. The average production yield of the quadrivalent VLPs exceeded 40 mg/L, an improvement over conventional yields. The candidate VLPs elicited strong HPV-specific IgG and neutralizing antibody responses in mice, comparable to those induced by Gardasil. Conclusions: The hyper-expression baculovirus vector system enables high-yield production of HPV L1 VLPs with desirable structural and immunogenic properties. This approach holds promise for the cost-effective and scalable manufacturing of next-generation HPV VLP vaccines, facilitating broader global access to HPV immunization.

Background/Objectives: Cervical cancer, predominantly driven by persistent infection with high-risk human papillomaviruses (HPVs), is one of the most common malignancies and an important cause of cancer-related mortality among women worldwide. Although existing licensed prophylactic HPV vaccines confer excellent protection, their global use remains suboptimal due to concentrated manufacturing capacity and high production costs. This study aimed to establish a cost-effective multivalent HPV virus-like particle (VLP) vaccine platform. Specifically, we used an enhanced baculovirus expression vector system to produce a 12-valent HPV VLP vaccine to improve antigen yield, thereby reducing manufacturing costs and ultimately improving affordability and availability in low- and middle-income countries. Methods: Optimized expression cassettes and an insect cell culture process were designed to enhance productivity across 12 HPV L1 genotypes. A scalable purification scheme integrating ion-exchange and adsorption chromatography was developed to produce high-purity VLPs with consistent structural integrity. Immunogenicity was assessed in a murine model. Elicited HPV type-specific IgG antibody responses were compared with those induced by the licensed 9-valent HPV vaccine. Results: The assembled 12-valent VLPs were comprehensively characterized using biophysical and immunochemical analyses, confirming structural stability and correct antigenicity. In vivo immunogenicity studies in mice showed strong and serotype-specific IgG responses, comparable or superior to those induced by the licensed 9-valent commercial vaccine. Conclusions: The enhanced baculovirus expression vector system is a versatile and economically sustainable platform for next-generation HPV vaccine production. This technology offers a promising approach to lowering vaccine manufacturing costs and improving global access, particularly in low- and middle-income regions heavily burdened by HPV-associated diseases.