The field efficacy and safety of a single-dose inactivated Mycoplasma hyopneumoniae
vaccine, Suvaxyn MH-One, was evaluated in 4-5-day-old piglets on a commercial farm with a history of Mycoplasma disease in Southern Germany. The piglets were injected intramuscularly with the
vaccine or saline (control group) and raised under commercial conditions to slaughter weight. The efficacy of the
vaccine was determined by comparing the lung lesions associated with
infection by M. hyopneumoniae in control and vaccinated pigs post mortem. In this analysis the vaccinated pigs had the lower mean percentage lung lesion at 5% compared to 9% in controls. Of the vaccinated pigs 52.3% were shown to have low levels of lung lesions between 0% and 5% and no more than 5.4% were shown to have levels above 20%. In contrast, the pigs administered saline showed 36.5% in the lower category (0-5%), while 18.3% showed lesions greater than 20%. There were significant differences in the mean
body weight of pigs at the final two weight measurements at approximately 21 weeks and 26 weeks of age, with those receiving Suvaxyn MH-One being on average 5 kg heavier at each time point. There was also a significant increase in average daily gain in the vaccinated animals compared to the control group, particularly in the period from vaccination to the final two
body weight measurements on day 138 and 166, from weaning at day 28 to the final two body measurements and from mid-way during finishing at day 84 to the final two
body weight measurements. Vaccination had no adverse impact on appetite, although small numbers of vaccinated and control pigs did show mild signs of coughing,
sneezing, respiratory distress or depression. There was no adverse impact on rectal temperatures and no signs of
injection site reactions during the course of the study. We can conclude that vaccination with Suvaxyn MH-One to pigs at less than 1 week of age is effective in reducing lung lesions resulting from M. hyopneumoniae and also
aids growth performance by reducing
weight losses and improving average daily gain.