Is there value in autogenous PRRS vaccination?
An Iowa State study reported at the 1999 Allen D. Leman Swine Conference evaluated the potential benefits of using an autogenous killed PRRS vaccine alone and in combination with a commercial modified live PRRS vaccine (Ingelvac
The researchers obtained an atypical PRRS strain (SDSU 73) from a herd showing severe reproductive problems, a strain shown in testing to cause both severe reproductive and respiratory disease. They then created a killed, adjuvanted vaccine from that same atypical strain and used it in a trial on 75 PRRS negative pigs randomly assigned to five treatment groups (figure 3.)
All pigs in the first four groups were challenged with virulent PRRS at 9 weeks of age. At necropsy, pulmonary scores, or gross lesion lung scores, were 26 percent, 8 percent, 6 percent, 47 percent and 1.5 percent for the five groups, respectively.
The work demonstrated that use of the commercial MLV vaccination significantly reduced lung lesions compared to unvaccinated animals. Killed vaccine alone failed to provide significant reduction in severity of PRRSV induced pneumonia lesions. Use of a killed vaccine in combination with the MLV did not provide significant additive benefits. Thus, a single dose of MLV PRRS vaccine provided statistically significant heterologous protection against respiratory disease from exposure to a highly virulent PRRS isolate.
To more information
Efficacy of a killed and modified live PRRS virus vaccine when used alone and in combination in growing pigs. Roof M, Halbur P, Burkhart K, Vaughn E. Allen D. Leman Swine Conference, Recent Research Reports, Sept 1999; 29.