Research Progress on the Development of Porcine Reproductive and Respiratory Syndrome Vaccines

Abstract

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease in the pig industry, but its pathogenesis is not yet fully understood. The disease is caused by the PRRS virus (PRRSV), which primarily infects porcine alveolar macrophages and disrupts the immune system. Unfortunately, there is no specific drug to cure PRRS, so vaccination is crucial for controlling the disease. There are various types of single and combined vaccines available, including live, inactivated, subunit, DNA, and vector vaccines. Among them, live vaccines provide better protection, but cross-protection is weak. Inactivated vaccines are safe but have poor immune efficacy. Subunit vaccines can be used in the third trimester of pregnancy, and DNA vaccines can enhance the protective effect of live vaccines. However, vector vaccines only confer partial protection and have not been widely used in practice. A PRRS vaccine that meets new-generation international standards is still needed. This manuscript provides a comprehensive review of the advantages, disadvantages, and applicability of live-attenuated, inactivated, subunit, live vector, DNA, gene-deletion, synthetic peptide, virus-like particle, and other types of vaccines for the prevention and control of PRRS. The aim is to provide a theoretical basis for vaccine research and development.

Synthetic Peptides Elicit Humoral Response against Porcine Reproductive and Respiratory Syndrome Virus in Swine

“…The commercially available MLVs vaccines fail to provide sufficient heterologous protection, as they typically induce weak innate and humoral responses, and inadequate T cell responses [ 22 , 23 , 24 , 25 , 26 ]. For instance, the antibody protection following vaccination is low and may result in antibody-dependent enhancement, facilitating virus entry [ 27 ]. Inactivated virus vaccines have shown poor efficacy, such as poor immune effects on heterologous strains, a lack of detectable PRRSV-specific antibody production, and an absence of a cell-mediated immune response [ 25 , 27 , 28 , 29 , 30 , 31 , 32 ].…”

“…For instance, the antibody protection following vaccination is low and may result in antibody-dependent enhancement, facilitating virus entry [ 27 ]. Inactivated virus vaccines have shown poor efficacy, such as poor immune effects on heterologous strains, a lack of detectable PRRSV-specific antibody production, and an absence of a cell-mediated immune response [ 25 , 27 , 28 , 29 , 30 , 31 , 32 ]. The high genetic and antigenic diversity presents a significant impediment to developing an effective vaccine to control PRRS.…”

“…Compared to commercial vaccines, peptide vaccines do not contain nucleic acid substances; therefore, they are considered safer [ 41 ]. Peptides contain only B or T epitopes that induce a specific response [ 27 , 41 ]. Likewise, adjuvants can enhance T or B cells’ responses by enhancing phagocyting activity and secreting a variety of cytokines that boost the specific immune response to the vaccine [ 32 , 42 , 43 ].…”

Induction of Specific IgG antibodies and B-Cell Mediated Immunity by Glycoprotein 5 Peptides in Porcine Reproductive and Respiratory Syndrome virus Infected Swine

“…These vaccines provide limited protection against homologous strains and little or no protection against heterologous strains, which are circulating and mutating in the field [10]. For instance, the antibody protection following vaccination is low and may result in antibody-dependent enhancement, facilitating virus entry [11]. The high genetic and antigenic diversity presents a significant impediment to developing an effective vaccine to control PRRS.…”

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“…The challenge of effectively preventing and controlling PRRS is a major bottleneck in healthy swine breeding today (2). Different regions employ various strategies for PRRS management; for instance, the European Union and the United States focus on biosecurity measures (3), whereas China and other countries rely on vaccination strategies (4). Although PRRS vaccines, including live and inactivated versions, do not offer universal protection against all strains, they are crucial in controlling the disease (5).…”