Protective effects of an oral microencapsulated Mycoplasma hyopneumoniae vaccine against experimental infection in pigs

Weng, Chung-Nan; Tzan, Y. L.; Liu, Shu Dong; Lin, Shan‐Yang; Lee, C.J.

doi:10.1016/0034-5288(92)90082-d

Cited by 20 publications

(10 citation statements)

References 12 publications

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“…The first group expressed a more systemic immunity while the second group enjoyed better local mucous immunity, which correlates with the existing literature (Weng et al, 1992). The decrease in the vaccine efficiency in the third group could be explained by reciprocal influence.…”

Section: Discussionsupporting

confidence: 78%

Mycoplasma hyopneumoniae Vaccination Influence on Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae Coinfection

Silin¹,

Lyubomska²,

Weng³

2001

Acta Vet. Brno

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Simultaneous vaccination against porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae can decrease the efficacy of the separate vaccination. The aim of present research was to clarify whether immunization against M. hyopneumoniae only protects against porcine reproductive and respiratory syndrome development. The challenge test with both porcine reproductive and respiratory syndrome virus and M. hyopneumoniae was performed in experimental conditions on swine groups with different immune protection against M. hyopneumoniae. The experiment was conducted on twenty specific pathogen free three-month-old piglets that previously acquired varying levels of protection against M. hyopneumoniae via oral or subcutaneous vaccination. The results suggest that M. hyopneumoniae initiates the pathogenic chain of M. hyopneumoniae -porcine reproductive and respiratory syndrome virus co-infection. Simultaneously vaccinated via oral and parenteral routes animals demonstrated maximal scoring of M. hyopneumoniae lesions (5.0 against 2.0 in control group), therefore such strategy seems unreasonable.The immunization against M. hyopneumoniae undoubtedly influences the development of porcine reproductive and respiratory syndrome virus -M. hyopneumoniae co-infection, however, the interactions between infectious agents and immune defense depend on the qualitative and quantitative parameters of immunity. These interactions are multi-factorial and too complicated for an absolutely correct prognosis. The protection against M. hyopneumoniae disease development can prevent or, at least, delay porcine reproductive and respiratory syndrome in piglets and vice versa: the lung lesions and immune suppression caused by M. hyopneumoniae can open the gate to porcine reproductive and respiratory syndrome virus, which additionally complicates pathogenesis and leads to unfavorable consequences. Porcine reproductive and respiratory syndrome virus (PRRSV

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Section: Discussionsupporting

confidence: 78%

Mycoplasma hyopneumoniae Vaccination Influence on Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae Coinfection

Silin¹,

Lyubomska²,

Weng³

2001

Acta Vet. Brno

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“…The results, however, were diverse. In some studies, vaccination failed to provide protective immunity (hfURPHY et al, KlNG et al, 1997) while in other studies, it turned out to confer beneficial effects ( KOBISCH et al, 1987;WENG et al, 1992). However, a challenge model in which high doses of Mh organisms are inoculated once or twice, may not be reliable to mirror the field situation of a chronic respiratory disease such as EP.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Vaccination againstMycoplasma hyopneumoniaein Pig Herds with a Continuous Production System

Maes

Deluyker

Verdonck

et al. 1998

Journal of Veterinary Medicine, Series B

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Wtb 7 bbkrsummary An inactivated M F p h a &peumnizc vaccine was evaluated in five pig herds clinically infected with enzootic pneumonia and practising a continuous production system in the growmg/finishmg unit. In each herd, a vacanated and control group of approximately 47 pigs each were individually monitored from birth until slaughter. Vaccinated pigs received the first dose at about 1 week of age and the second approximately 3 weeks later. During all production stages, an equal number of vaccinated and control pigs was present in the same pen. Both groups were compared with respect to zootechnical parameters (major variables) and by means of serological, pathologicd, and bacteriological parameters (ancillary variables). Daily weight gain was im roved by 14 @/day during the period from 8 days of age until slaughter (P = 0.0486) and by 25 @/!lay during the growmg/finishing period (P = 0.0067). Mortality rate, and the costs for curative medication were not significantly improved by vaccination. The results of the andllary variables are presented and discussed.

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“…Pigs also show some signs of protection after intramuscular inoculation with formalin-inactivated M. hyopneumoniae vaccine, and a booster inoculation with the same vaccine onto the mucosal surface of Peyer's patches via surgical operation [26]. This information indicates that the primary goal of mucosal immunization is to induce secreted antibodies into mucosal surfaces, both at the immunization site and at distant surfaces, and that serum IgA is a crucial factor in protecting pigs from M. hyopneumoniae infection.…”

Section: Discussionmentioning

confidence: 91%

“…Group Mix received an intramuscular injection on day 0, and M. hyopneumoniae oral vaccine on days 10 and 20, whereas groups NV/C and NC were fed a placebo. All 24 piglets in groups Eu, IM, Mix and NV/C were challenged on day 30 with 5 ml of 10% pneumonic lung homogenate suspension containing 10 7 CCU of M. hyopneumoniae [26], via intubation of the trachea.…”

Section: Preparation Of Microspheresmentioning

confidence: 99%

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Protective Effects of Oral Microencapsulated Mycoplasma hyopneumoniae Vaccine Prepared by Co-Spray Drying Method.

et al. 2003

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ABSTRACT. The efficacy of Mycoplasma hyopneumoniae oral vaccine was investigated in microsphere dosage form. A co-spray drying process was used to apply an encapsulating material, Eudragit L30 D-55, to microspheres containing Mycoplasma hyopneumoniae antigens. The microspheres were generally effective (>93%) with protein release at pH 7.4, but almost none were released at pH 1.2, for 3 hr in an in vitro dissolution test. An SPF-swine model was used to evaluate the effectiveness of the microspheres as an oral vaccine, and the related immune responses. The serum's systemic IgG against M. hyopneumoniae was evoked by ELISA analysis, after a 2nd immunization of all pigs. The vaccinated groups' mean lesion score was significantly lower after the Mycoplasma hyopneumoniae challenge than that of the nonvaccinated/challenged groups (P<0.05). This study strongly suggests that the oral microspheres vaccine prepared by a co-spray drying method can provide effective protection against M. hyopneumoniae infection in pigs. KEY WORDS: co-spray drying, microsphere, Mycoplasma hyopneumoniae, oral vaccine.J. Vet. Med. Sci. 65(1): 69-74, 2003 Mycoplasma hyopneumoniae is widely recognized as a potent pathogen for mycoplasmal pneumonia in swine [2], colonizing the respiratory epithelia and compromising integrity by inducing an inflammatory response [20]. The pathogen also causes significant economic losses by reducing body weight and prolonging periods between feeds [22]. Although some drugs and antibiotics are effective in vitro against M. hyopneumoniae, reducing the disease's clinical signs [12], they have not yet been proven effective in eliminating the pathogen in vivo. Vaccination is an essential strategy in controlling mycoplasmal pneumonia. M. hyopneumoniae infects the ciliated epithelial cells of the respiratory tract [6], and a mucosal immune response may therefore be important in the prevention and control of M. hyopneumoniae-induced pneumonia [23]. The concept of a common mucosal immune system has been supported by several oral immunization reports [8,13]. Numerous experimental systems have proven that oral immunization can induce antibody secretion into the mucus on these surfaces [8,16,18], and is almost completely restricted to the secretory form of IgA. Oral immunization causes this IgA antibody to be secreted from the GALT to distant mucosal tissue, including the salivary, mammary, respiratory, intestine and genital mucosal tissue, protecting these areas from pathogen invasion [5,14].Microspheres have recently received widespread interest as vehicles for the controlled release of drug or bioactive agents; resisting degradation in gastric acid, they can release drugs in the intestines [1]. Oral antigen delivery by pHdependent microspheres can improve local and systemic immune responses [4,16], serving as a potent mucosal immunogen. It is essential to develop a new, simple and effective vaccine process. Microsphere oral vaccines have been previously developed in our laboratory via a novel cospray-drying process [16]. C...

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Protective effects of an oral microencapsulated Mycoplasma hyopneumoniae vaccine against experimental infection in pigs

Cited by 20 publications

References 12 publications

Mycoplasma hyopneumoniae Vaccination Influence on Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae Coinfection

Mycoplasma hyopneumoniae Vaccination Influence on Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae Coinfection

The Effect of Vaccination againstMycoplasma hyopneumoniaein Pig Herds with a Continuous Production System

Protective Effects of Oral Microencapsulated Mycoplasma hyopneumoniae Vaccine Prepared by Co-Spray Drying Method.

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