Modeling Economic Effects of Vaccination Against Porcine Reproductive and Respiratory Syndrome: Impact of Vaccination Effectiveness, Vaccine Price, and Vaccination Coverage.

Beat Thomann,Gertraud Schuepbach-Regula,Heiko Nathues,Jonathan Rushton

doi:10.3389/fvets.2020.00500

Abstract

Porcine reproductive and respiratory syndrome (PRRS) causes substantial financial losses in pig farms and economic losses to societies worldwide. Vaccination against PRRS virus (PRRSV) is a common intervention in affected farms. The aim of this study was to assess the economic impact and profitability of potential new PRRS vaccines with improved efficacy at animal, herd, and national level. Two vaccination strategies were modeled; (i) mass vaccination of sows only (MS) and (ii) mass vaccination of sows and vaccination of piglets (MSP), comprising different scenarios of vaccine effectiveness, vaccine price, and vaccination coverage. A farrow-to-finish farm with 1,000 working sows from a pig-dense region in Germany served as an example farm. Financial benefits were obtained from gross margin analyses and were defined as difference in gross margin between a PRRSV-infected farm without vaccination (baseline) and with vaccination (intervention). Financial benefits were highest if both sows and piglets (MSP) were vaccinated. In these scenarios, median annual net benefits per working sow ranged from €170 to 340. If sows only were vaccinated (MS), estimated benefits attributable to vaccination were between €148 and 270. Decisive variables for the estimation of national level benefits were the number of farmers switching from existing to a better protecting vaccine, the number of previously non-vaccinating herds adopting the new vaccine, and the effectiveness of the new vaccine relative to those already available. Benefits were greatest when the new vaccine was adopted by previously non-vaccinating herds. The analyses showed that vaccination against PRRS was beneficial for all modeled scenarios. The magnitude of benefits derived from vaccination was more susceptible to changes in vaccination effectiveness than to vaccine price changes. This study provides evidence to support future vaccine development. The estimates indicate that the introduction of more efficient vaccines might lead to substantial financial benefits, is of socio-economic importance and that new vaccines might significantly contribute to the reduction of disease burden.

Highlights

Porcine reproductive and respiratory syndrome (PRRS) causes substantial economic losses in pig production worldwide [1,2,3,4]
Financial losses due to PRRS, expressed as difference in gross margin between a PRRS virus (PRRSV) negative and a PRRSV-infected farrowto-finish farm with disease effects according to Table 2 and 1,000 working sows were e400,018 per year (Figure 1)
The magnitude of financial benefits generated was more sensitive to a change in vaccination effectiveness than the variation of vaccine price

Summary

Introduction

Porcine reproductive and respiratory syndrome (PRRS) causes substantial economic losses in pig production worldwide [1,2,3,4]. Costs due to PRRS depend on the individual farm situation including factors such as disease severity, affected production stages, or farm size. Median losses in a farrow-to-finish farm in Germany with 1,000 working sows moderately affected in all production stages were estimated at e 442′973 per year [3]. Both the reproduction component of the disease manifested in breeding sows and the respiratory component in growing pigs contribute substantially to the economic losses [2, 3]. Depending on individual farm situation, several intervention strategies have shown to be profitable, with mass vaccination of sows or mass vaccination of sow and piglets being amongst the most cost efficient control strategies [6]

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Conclusion