UK - Major field study on M. hyo vaccines results revealed

The results of one of the largest abattoir surveys ever conducted, which examined more than 80,000 lungs from more than 800 farms, were presented at the recent International Pig Veterinary Society Congress in Hamburg. It provided pig vets and producers with interesting statistics on the efficiency of the current range of commercially available Mycoplasma hyopneumoniae vaccines. Checking lung lesions at slaughter is an important tool for vets to better monitor the health status of farms under their supervision but seldom has there ever been a study of such a size and consistency. Seven technicians were hired and trained at the same time for lung lesions scoring by The Institut des Productions Animales et des Industries Agro-alimentaires - 22 Ploufragan (ISPAIA) and then allocated to one of 6 slaughterhouses servicing more than 800 farms. Those slaughter houses represent approximately 35 % of the total French production. Lung lesions were quantified using recognised scoring methods and each lung lobe was scored on a scale between 0 (no lesion) and 4 (worse possible lesion) giving an overall maximum possible score of 24 (the accessory lobe was not scored). Results were analysed in groups determined by the Mycoplasma vaccines used on the different farms. Pigs vaccinated with Stellamune® Mycoplasma, Stellamune® Once, Suvaxyn® M hyo, Ingelvac® M hyo, Hyoresp®, M+Pac ® or non vaccinated were included in the study. When more than one vaccine was used during the study period, the batches were assigned to an "unknown" group and removed from the analysis. A total of 1,220 batches of pigs were scored of which 80% were vaccinated. The average lung score was significantly improved by vaccination (p = 0.05) as compared to unvaccinated controls confirming for farmers a positive return on investment. When comparing the performance of different vaccines used in the study, Ingelvac® M hyo performed significantly better than the other one-dose vaccine and most of the two-dose vaccines. Although all the included farms are not directly comparable because of the different health status and management practices used, the massive size of the study does provide a valuable insight into the performance of the different Mycoplasma vaccines used. Although there was no significant performance difference between pigs vaccinated with a 1-dose and a 2-dose vaccine (p>0.05) when analysed together, the study confirmed the reliable efficacy provided by more convenient one-dose vaccines. This study confirmed that vaccination against M. hyopneumoniae has a positive effect on lung health which proved to be statistically significant. It shows that all M hyo vaccines are not "the same" and the improved delivery systems such as the Impran® Adjuvant System in Ingelvac M hyo may be the basis of the improved efficacy provided.