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.