[Application and research progress in porcine circovirus type 2 vaccines]

Porcine circovirus associated disease (PCVAD) is an immunosuppressive disease caused by porcine circovirus (PCV), which has led to substantial economic losses in the swine industry. Porcine circovirus type 2 (PCV2) is the primary genotype responsible for PCVAD and the most prevalent pathogenic agent. PCV2 infection can induce lymphoid depletion, immunosuppression, and multi-systemic lesions, severely compromising pig health and production performance. Since no specific antiviral drug against PCV2 is available, vaccination becomes the primary strategy for disease prevention and control. Currently, commercial vaccines, predominantly inactivated and subunit vaccines, play a crucial role in controlling PCVAD. In recent years, advances in genetic engineering have significantly propelled the development of novel vaccines, including virus-like particle vaccines, live vector vaccines, transgenic plant-based vaccines, nanoparticle vaccines, and nucleic acid vaccines. However, the high mutation rate of PCV2 and the emergence of new genotypes have resulted in reduced efficacy of existing vaccines against newly circulating strains, posing ongoing challenges to disease control. This review systematically summarizes the etiological characteristics of PCV2 and the current landscape of vaccine development and application, with a particular focus on commenting on the progress in novel vaccine research. Finally, we prospect future directions for vaccine development, aiming to provide a scientific basis and technical references for the effective prevention and control of PCVAD.