Field evaluation of the efficacy, compatibility and serologic profiling of a combined vaccine against porcine reproductive and respiratory syndrome and Haemophilus parasuis in nursery pigs

Abstract

The aim of the study was to compare the efficacy and compatibility of a separate or combined vaccination against the porcine reproductive and respiratory syndrome (PRRS) and Haemophilus (H.) parasuis. The study was conducted in a 1200 head nursery farm. A total of 360 piglets at an age of 26 days were randomized into three groups. Group A was vaccinated separately against H. parasuis (Porcilis®Glässer) and PRRS (Porcilis®PRRS), group B was vaccinated with a combined vaccine of both vaccines and group C remained unvaccinated as control group. The compatibility was evaluated by measurement of the body temperature and a palpation score of the injection site 0, 4, 24 and 72h after vaccination. During the nursery and the fattening period the average daily weight gain (ADWG), the number of runts and the mortality was evaluated. Additionally blood samples were taken every 2 weeks during the nursery period to perform an OppA-ELISA and a PCR for PRRS virus. No significant difference could be seen regarding the body temperature between group A and group C. Piglets which were vaccinated with the combined vaccine showed a significantly higher body temperature 4 and 72h post vaccination than piglets from group A. The palpation score was significantly higher in group A 4 and 24h post vaccination compared to the control group, whereas no significant difference was observed between group A and B. No significant differences between groups were seen in the ADWG during the nursery period. The mortality rate during the nursery period was significantly higher in group C than in group A. The ADWG during fattening was significantly higher in the vaccinated groups than in group C. A PRRS genotype1 field virus was detected at the end of the nursery period. No significant differences were observed in the number of OppA-ELISA positive animals, but vaccinated pigs seemed to react earlier. All pigs of the vaccinated groups that were positive in the OppA-ELISA did not develop Glässer's disease and remained in the study until slaughter. The combined administration had no negative influence on efficacy but showed a slightly worse compatibility than the separate administration of both vaccines. The results of the present study indicate that vaccination against Glässer's disease using Porcilis®Glässer might influence the results of the OppA-ELISA.