Date Full Report Received


Date Abstract Report Received



Primary Investigator:

The objective of this project was to determine the full length sequences of an interferon-inducible PRRSV strain A2MC2 and determine whether it can induce neutralizing antibodies. Type I interferons (IFNs), such as IFN-α and -β, are critical to antiviral innate immunity and play important roles in the modulation of adaptive immunity. In this study, full length sequence of the A2MC2 genome was determined. Sequence analysis indicated that it is highly homologous to VR-2332, the prototype of North America PRRSV genotype. A2MC2 induction of neutralizing antibodies was compared with the Ingelvac PRRS modified live virus (MLV) vaccine strain and VR-2385 (a moderate virulent strain). Three-week-old pigs were exposed to these PRRSV strains via intranasal or intramuscular routes to also account for a possible effect of inoculation routes. The A2MC2 resulted in earlier onset and significantly higher levels of PRRSV neutralizing antibodies than the MLV. In addition, the A2MC2-induced neutralizing antibodies were capable of neutralizing VR-2385, a heterologous strain. The pigs exposed via intranasal route had higher titers of neutralizing antibodies than those injected via intramuscular route. These results indicate that PRRSV A2MC2 is able to induce higher level neutralizing antibodies, which may be because of the strain property in interferon induction. This information will be helpful in designing an improved vaccine to combat PRRS. For further information, please contact Dr. Zhang at zhangyj@umd.edu.