Research progress for vaccines against pivotal swine viruses

Porcine viral diseases, characterized by high infectivity and virulence, represent a significant challenge to global swine production. Although vaccination remains the cornerstone of disease control, the rapid evolution of viral genotypes and the prevalence of co-infections have undermined the field efficacy of existing vaccines. The porcine reproductive and respiratory syndrome virus (PRRSV), African swine fever virus (ASFV), porcine epidemic diarrhea virus (PEDV), and porcine circovirus type 2 (PCV2) pose particular challenges in industrial pig farming. This review focuses on the research progress of vaccines targeting these four viruses across various technical platforms, including live attenuated vaccines (LAVs), inactivated vaccines (IVs), subunit vaccines, and nucleic acid vaccines. By analyzing the immunological strengths and safety challenges of both traditional and emerging strategies, we aim to outline future directions in vaccine engineering and provide insights into optimizing immunization protocols against these persistent viral threats.