Efficacy of a new ready-to-use vaccine against PCV-2d and Mycoplasma hyopneumoniae under experimental conditions

<i>Mycoplasma hyopneumoniae</i> (<i>M. hyo</i>) and porcine circovirus type 2 (PCV-2) are major and widespread swine pathogens, both implicated in the porcine respiratory disease complex, which can lead to significant economic losses for pig producers. PCV-2d is currently the most prevalent genotype. Vaccination against these two pathogens helps mitigate their impact on pig health and performance. The use of ready-to-mix or ready-to-use (RTU) vaccines targeting PCV-2a or PCV-2a/b and <i>M. hyo</i> is a common practice. This study aimed to evaluate the efficacy of a novel RTU vaccine containing PCV-2d and <i>M. hyo</i> antigens under experimental conditions. Several challenge trials were conducted using PCV-2a, PCV-2b, PCV-2d, and <i>M. hyo</i> to assess the level of protection conferred against different PCV-2 genotypes and <i>M. hyo</i>, as well as to determine the duration of protection. This study demonstrated that the bivalent PCV-2/<i>M. hyo</i> vaccine induces both early and long-lasting protection against infections caused by <i>M. hyo</i> and PCV-2. In addition, cross-protection against the three major PCV-2 genotypes was confirmed.