Efficiency of inactive vaccines against contagious agalactia in Brazil

Abstract

This paper aims to evaluate the efficiency of three inactive vaccines against contagious agalactia prepared with samples of Mycoplasma agalactiae isolated in Brazil and different adjuvants. Vaccine 1 adsorbed with aluminum hydroxide was administered in 23 goats (Gc1) and 13 sheep (Gov1); vaccine 2 containing Montanide IMS-2215-VG was administered in 22 goats (Gc2) and 12 sheep (Gov2) and vaccine 3, containing Montanide Gel-01 was administered in 22 goats (Gc3) and 12 sheep (Gov3). All animals were negative for Ma at indirect ELISA and received two doses of 2mL each, subcutaneously, within a 21 day interval. Five animals from each species were used as control. Seventy-five days after the booster, four animals from each vaccinated group and two from the control group were challenged with 5mL of Ma culture containing 10 7 cfu/mL, orally and through immersion of the female's udder in lactation. The serological response was analyzed during vaccination days (0 and 21) and at 51, 81, 111, 141 and 171 days after vaccination. The collection and analysis of the challenged animals were conducted at the day of the challenge (D0) and 7, 14, 21, 28, 35, 42, 49 and 56 days after the challenge. The three vaccines induced the production of antibodies, having no significant statistical difference (p<0.05). Animals from groups Gc1, Gc2 and Gov2 developed higher levels of antibodies, with significant statistical difference compared to the other vaccinated group and control group (p<0.05). After the challenge, the animals from the control presented an increase in regional lymph nodes and conjunctivitis, mastitis and arthritis. In four vaccinated animals, discrete conjunctivitis and congestion of the episcleral veins was observed. It is concluded that vaccines 1 and 2 induced levels of protective antibodies in goats and sheep, sufficient for clinical protection of the animals submitted to the experimental infection, indicating its use on the prevention of contagious agalactia.Keywords: Mycoplasma agalactiae, goats, sheep, immunization, ELISA RESUMO Este trabalho tem como objetivo avaliar a eficácia de três vacinas inativadas contra agalaxia contagiosa, preparadas com amostra de Mycoplasma agalactiae isolada no Brasil e diferentes adjuvantes. A vacina 1, adsorvida com hidróxido de alumínio, foi administrada em 23 caprinos (Gc1) e 13 ovinos (Gov1); a vacina 2, contendo Montanide IMS-2215-VG, foi administrada em 22 caprinos (Gc2) e 12 ovinos (Gov2); e a vacina 3, contendo Montanide Gel-01 foi administrada em 22 caprinos (Gc3) e 12 ovinos (Gov3). Todos os animais eram negativos para

Granulomas Following Subcutaneous Injection With Aluminum Adjuvant-Containing Products in Sheep

“…3,16,17 Sheep are considered prone to the development of vaccine-associated granulomas 37,40 and preclinical safety studies for sheep vaccine development usually include periodical in vivo evaluation of the reactions at the injection site over a period of a few months. 2,33 There are no reported histologic descriptions of the acute or subacute inflammatory response to vaccines. 15 Moreover, a complete pathologic characterization of vaccine-induced granulomas in sheep, including location of Al within granulomas and lymph nodes, has never been performed.…”

“…3,16,17 Sheep are considered prone to the development of vaccine-associated granulomas 37,40 and preclinical safety studies for sheep vaccine development usually include periodical in vivo evaluation of the reactions at the injection site over a period of a few months. 2,33…”

Mycoplasma agalactiae Vaccines: Current Status, Hurdles, and Opportunities Due to Advances in Pathogenicity Studies

“…Experimental challenges with large groups, especially with lactating animals and in restricted areas, are serious limitations. Few challenge models have been described, for instance, keeping vaccinated animals in contact with animals from herds where the presence of M. agalactiae had previously been detected [ 42 ], or immersing the animals’ udders in a solution containing a bacterial culture [ 44 ], or via the intramammary [ 41 ] and nasal routes [ 45 ]. However, the absence of a smaller animal model and a dearth of specific kits to evaluate the immune responses of goats and sheep are a big hindrance and delay the development of new vaccine alternatives.…”

<p>Contagious Agalactia In Sheep And Goats: Current Perspectives</p>

“…The strain included in the vaccine as well as the inactivation method and the adjuvant used are all key factors for immunogenic efficacy against potentially very variable infective strains 184–186. Mineral-oil adjuvant-inactivated vaccines induce higher and longer-lasting protective immunity than the aluminium-hydroxide-absorbed vaccines, but they can also induce lesions at the injection site 176,179,182,187. Inactivated vaccines remain sub-optimal, as most of the time they reduce clinical severity rather than preventing new infections or even milk excretion 49,180,184.…”