A field efficacy and safety trial in the Netherlands in pigs vaccinated at 3 weeks of age with a ready-to-use porcine circovirus type 2 and Mycoplasma hyopneumoniae combined vaccine

Abstract

BackgroundRespiratory diseases impair the health and welfare of growing pigs and impacts farmers’ gains worldwide. Their control through a preventative medical approach has to be tailored according to the pathogens identified at farm level. In the Netherlands, several studies have emphasized the prominent role of Mycoplasma hyopneumoniae, Porcine Circovirus type 2 and Porcine Reproductive and Respiratory Syndrome Virus in such respiratory conditions. Further to the arrival on the Dutch market of the first commercially available bivalent vaccine against PCV2 and M. hyopneumoniae, Porcilis® PCV M. Hyo, a trial was designed to evaluate its safety and efficacy under local field conditions.Material and methodsIn a conventional farrow-to-finish 170-sow farm with a history of respiratory diseases and demonstrated circulation of both M. hyopneumoniae and PCV2, 812 piglets were randomised and included at weaning in either of the three following groups: PCVM (vaccinated with Porcilis® PCV M. Hyo), FLEX (vaccinated with CircoFLEX® and MycoFLEX®) or NC (negative control, injected with placebo). Piglets were vaccinated at 3 weeks of age (day 0) and a subset was bled and weighed at regular intervals up to slaughter. Lung slaughter checks were only performed on 64% of the pigs included on day 0.Results and implicationNo side effect of injection was observed in any of the three groups. Average daily weight gain was improved in both vaccinated groups as compared to the NC group, over the finishing period as well as from wean-to-finish. The PCVM group had a significantly lower PCV2 viremia area under the curve than the two other groups, and a significant reduction in the severity of the pneumonia-like lesions was observed at slaughter in the pigs of the PCVM group. A conservative estimate of the economic benefit of that vaccine was 2.84 € per finisher. This trial confirms that the vaccine is efficacious against the health and growth effects of PCV2 and M. hyopneumoniae, of practical advantage (single injection of a bivalent product) and well tolerated.

Efficacy of Two Commercial Ready-To-Use PCV2 and Mycoplasma hyopneumoniae Vaccines under Field Conditions

“…Our results are consistent with previous field studies that used these or other PCV2-M. hyopneumoniae bivalent vaccines [24,26], showing that bivalent vaccination reduces the number of infected animals and the viremia. However, in this study two points should be highlighted.…”

“…Although the difference in the mortality rate was not significant, we observed a slight improvement in both vaccinated groups for this parameter. In the case of the ADWG, as in other comparatives studies of bivalent PCV2-M. hyopneumoniae vaccines, no variation between the three groups was found over the nursery period, although differences emerged during the fattening phase; this was to be expected, as both infections occurred at this stage [24,25]. Using the unvaccinated group as a reference, the improvement in the ADWG was only significant in Group A.…”

Comparison of Mycoplasma hyopneumoniae and porcine circovirus 2 commercial vaccines efficacy when applied separate or combined under experimental conditions

“…Besides the lower labour expenses, other factors such as animal welfare (lesser number of injections and manipulations) and lower risk of other pathogen transmission (through syringes and needles) account importantly as benefits of a single injection of two vaccine products. In some cases, however, a suspicion of lesser effectivity of these combined products has been suggested [15], posing doubts on their overall benefit. In fact, these later authors attributed such questionable efficacy to the variation of the epidemiology of respiratory diseases among farms and regions [15], claiming about the scarcity of comparative data on single-shot two valence vaccines.…”

“…In some cases, however, a suspicion of lesser effectivity of these combined products has been suggested [15], posing doubts on their overall benefit. In fact, these later authors attributed such questionable efficacy to the variation of the epidemiology of respiratory diseases among farms and regions [15], claiming about the scarcity of comparative data on single-shot two valence vaccines.…”

Immune responses induced by a combined vaccination with a recombinant chimera of Mycoplasma hyopneumoniae antigens and capsid virus-like particles of porcine circovirus type 2

“…The development of combined vaccines or combined vaccination strategies has gradually become the main trend to adapt to the needs of the market. Recently, researchers evaluated some of these combined vaccines and obtained good results in the immune reaction induced by them in mice or pigs [26][27][28][29][30]. Combined vaccines can not only reduce cross-infection between diseases but can also reduce the labor of animal keepers.…”