Year: 2026
Type: article
Abstract: Porcine reproductive and respiratory syndrome (PRRS) remains one of the most economically devastating diseases in global swine production. The causative agent, PRRS virus (PRRSV), comprises two genetically distinct species-PRRSV-1 and PRRSV-2-that differ substantially in antigenic composition and immune recognition. Despite widespread use of modified live vaccines (MLVs), protection against heterologous and cross-species strains remains inconsistent and difficult to predict. This review synthesizes current knowledge of homologous, heterologous, and cross-species protection, with emphasis on humoral and cellular immune responses and the viral determinants that constrain breadth of immunity. Neutralizing antibodies can confer near-sterilizing homologous protection under controlled conditions; however, their delayed induction and narrow specificity limit efficacy against heterologous strains. T-cell-mediated responses are generally broader but remain highly strain- and context-dependent. Structural features of PRRSV envelope glycoproteins, including glycan shielding and immunodominant decoy epitopes, further restrict antibody-mediated cross-protection while providing targets for rational vaccine design. We also examine potential drawbacks of preexisting immunity, including antigenic mismatch and non-neutralizing antibody-dominated responses that may contribute to suboptimal outcomes following heterologous exposure. Collectively, these findings highlight the multifactorial nature of PRRSV protection and the need for next-generation vaccines capable of inducing broader and more durable immunity.
Source: Pathogens
Institution: Kansas State University
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,654
OpenAlex ID: W7140179152