A Systematic Evaluation of the Evidence for Porcine
Reproductive and Respiratory Syndrome Vaccine Efficacy on
Reproductive Performance in Sows
Porcine Reproductive and Respiratory Syndrome (PRRS) virus was estimated in 2005 to cost U.S. pork producers $560 million annually, of which $67 million was attributed to reproductive disorders in breeding herds. The objective of this report was to provide a comprehensive, systematic review and quality assessment of all available research reports evaluating the use of commercial PRRS vaccines in breeding stock. To achieve the study objective, the systematic review methodology was adopted. The objective of this review therefore was to answer the question, “What is the effect of vaccination with a commercially available PRRS vaccine on the reproductive performance of breeding age female swine?” Four components of the question for a systematic review for an intervention consist of the population of interest, intervention, comparator, and outcome of interest (PICO). All potentially relevant primary research studies were identified, screened for relevance, assessed for standard design features, and if passing both the relevance and quality criterion, were extracted. The evaluation allows us the conclusion that there is a large volume of evidence discussing the effects of PRRS vaccination on reproductive parameters, but the studies are variable in the consistency of reporting and the approach used to measure these values. Based on the evidence gathered from this systematic review a positive benefit on reproductive parameters is reported with the use of vaccination. Practitioners bear the responsibility of assessing the validity of the experimental design and analysis as part of determining the evidentiary value of the conclusions relative to the vaccination decision they are making.