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Simultaneous (mixed) use of existing swine vaccines against porcine circovirus 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo) from Intervet/Schering-Plough Animal Health in swine are as efficacious and safe as separate use of these vaccines. This conclusion was drawn from several presentations this week at the 21st International Pig Veterinary Society (IPVS) congress, which took place this week in Vancouver BC (Canada). The vaccines discussed in this press release are not approved for simultaneous use. The described studies are part of ongoing investigations into PCV2 and M. hyo vaccines.“Worldwide more than 70 percent of piglets reared on industrialized farms are vaccinated against PCV2 and M. hyo virus infections. Interference between antigens resulting in decreased immune response is not unusual when different antigens are combined. Therefore, it is common practice that any combination of vaccines is tested in relevant and appropriate experimental settings, both under laboratory and field conditions”, explained Alex Eggen, DVM and Technical Lead for swine at Intervet/Schering-Plough Animal Health.
In a randomized, controlled challenge study presented at the conference, individual vaccines as well as various mixed vaccines were tested in 7 groups of 8 piglets with maternally derived antibodies. It was demonstrated that simultaneous use of PORCILIS® PCV and PORCILIS® M. hyo or PORCILIS® PCV and M+PAC® provided similar levels of protection against PCV2 and M. hyo infection as compared to separate injections with these vaccines. Moreover, there were no local or systemic reactions after vaccination in any of the vaccinated animals.
In a study in a closed farrow-to-finish herd in North-eastern Spain comparing the simultaneous and separate use of PORCILIS® PCV and PORCILIS® M. hyo (N=515) under field conditions, there were no marked differences between groups in immune responses or local or systemic reactions. Moreover, no differences were reported on lung lesion score between the two vaccineated groups, but the lung lesion scores of both vaccined groups were superior to the unvaccinated animals. In another field study performed at the same cooperative, the effects of separate and simultaneous use of PORCILIS® PCV and M+PAC® (N=397) were investigated. No differences between groups in immune responses were observed and there were no marked differences between groups with respect to local or systemic reactions.
Simultaneous use of these vaccines is expected to significantly improve convenience for swine veterinarians, resulting in more efficient animal husbandry. As a consequence, simultaneous use of these vaccines is also expected to result in lower costs for the farmer. Moreover, the reduction of the number of animal interventions and injections is also expected to reduce stress and therefore may lead to an overall improvement in animal welfare.
Infection of pigs with PCV virus and M. hyo is a concern in the pig industry as these infections cause significant morbidity, mortality and economic losses. Infection with PCV2 virus is known to cause a variety of syndromes in pigs, together known as PCVD. Symptoms may include clinical signs such as weight loss or failure to grow, enlarged lymph nodes, difficulty in breathing, pale skin and jaundice. Infection with M. hyo leads to pathologic lung lesions. Mixed infections occur frequently and interact with each other in a complicated way, resulting in potentiation of symptoms and progressive growth retardation.
