In vivo and in vitro comparisons of spray-drying and solvent- evaporation preparation of microencapsulated Mycoplasma hyopneumoniae for use as an orally administered vaccine for pigs.
OBJECTIVE
To evaluate the efficacy of an orally administered vaccine of Mycoplasma hyopneumoniae that was prepared by spray drying or solvent evaporation.


METHODS
Thirty 6-week-old, crossbred, specific-pathogen-free (SPF) pigs.


METHODS
Pigs were randomly allocated into 5 groups and housed in an SPF facility. Pigs in 2 groups (groups AQ and CAP) were fed M hyopneumoniae enteric-coated vaccine on days 0, 10, and 20. A third group (group IM) received an IM injection of M hyopneumoniae vaccine with aluminium hydroxide as an adjuvant on days 0, 10, and 20. The last 2 groups (non-vaccinated-challenged [NV-C] and nonchallenged [NC]) were fed a sham treatment. All 24 pigs in groups AQ, CAFP IM, and NV-C were challenge exposed with 5 ml of a 10% pneumonic lung suspension administered on day 40 via intubation of the trachea. All pigs were slaughtered and the lungs removed and examined for lesions on day 68.


RESULTS
In vitro studies indicated that these 2 microencapsulation techniques formed an effective shell and protected mycoplasmal antigen from gastric acid. Results of inoculation and challenge tests indicated that microencapsulated M hyopneumoniae were sufficiently potent to induce an immune response and provide good protection.


CONCLUSIONS
Orally administered microencapsulated M hyopneumoniae vaccines induced an immune response and reduced the severity of lung lesions in challenge-exposed pigs. Results suggest that this novel method can be applied to other antigens, because the spray-drying process yielded an orally administered M hyopneumoniae vaccine that induced a good immune response.
Lin
J H
JH
Department of Veterinary Medicine, National Taiwan University, Taipei, Republic of China.
Pan
M J
MJ
Liao
C W
CW
Weng
C N
CN
D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology; D003692:Delayed-Action Preparations; D005243:Feces / Q000382:microbiology; D007273:Injections, Intramuscular / Q000662:veterinary; D008863:Microspheres; D009174:Mycoplasma / Q000276:immunology*; D009297:Nasal Mucosa / Q000382:microbiology; D045729:Pneumonia of Swine, Mycoplasmal / Q000276:immunology / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D011897:Random Allocation; D012463:Saliva / Q000382:microbiology; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D003692:Delayed-Action Preparations