DETERMINATION OF THE EXISTENCE OF ANTIGENIC GROUPS IN EUROPEAN-TYPE PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS ISOLATES

摘要

Porcine reproductive and respiratory syndrome virus is highly heterogenic. Significant differences between different isolates have been encountered at the genomic level. However, no information is available about the possible influence of the genomiccloseness or distance in antigenic heterogeneity, even though the degree of antigenic similarity between two different isolates can be of paramount significance for cross-protection. Although the mechanisms involved in protective immunity have not been completely defined, neutralizing antibodies are thought to be important contributors (1). Furthermore, cross-neutralization has been used to typify other RNA viruses such as Foot and Mouth Disease virus (2), for which antigenic relatedness is essential toachieve protection. The objective of the present study was to determine whether European-type PRRSV isolates can be typified in antigenic groups by their cross-reactivity in seroneutralization assays.