Safety of Revaccination of Pregnant Bison With Brucella Abortus Strain Rb51

Abstract

From December 1998 through February 1999, a study was conducted in a Brucellainfected bison herd to evaluate the safety of booster vaccination of adult bison (Bison bison) with 6ϫ10 9 colony forming units (CFU) of Brucella abortus strain RB51 (SRB51) that had previously been vaccinated as yearlings with 1ϫ10 10 CFU of SRB51. Abortions or other adverse effects were not observed after SRB51 booster vaccination. At 10 wk after adult vaccination, pregnant and nonpregnant bison (nϭ65) were randomly selected for bacteriologic sampling of targeted maternal tissues during abattoir processing. Fetal tissues were also sampled in pregnant bison. The SRB51 vaccine was recovered from tissue samples of eight of 48 pregnant bison and none of 17 nonpregnant bison. In three of the eight culture-positive bison, SRB51 was recovered from fetal tissues. In three additional bison, one pregnant and two nonpregnant, B. abortus biovar 1 field strain was recovered from internal iliac or supramammary lymphatic tissues. Results of this study suggest the possibility that the SRB51 vaccine can be safely used to booster vaccinate pregnant bison in a Brucella-infected bison herd. Our data also reaffirms the potential for B. abortus field strains to persist in bison until attainment of reproductive age, despite extensive use of vaccination and serologic testing.

Ontology-Based Meta-Analysis of Animal and Human Adverse Events Associated With Licensed Brucellosis Vaccines

“…For inoculation methods ( Figure 6E ), subcutaneous vaccination is the most commonly used vaccination route ( Beckett and MacDiarmid, 1985 ; Elzer et al, 1998 ; Olsen and Holland, 2003 ; Ebrahimi et al, 2012 ; Singh et al, 2012 ). Conjunctival vaccination was associated with the highest abortion rate ( Zundel et al, 1992 ).…”

Progress in Brucella vaccine development

“…One study has found the incidence of abortion due to B. abortus challenge is significantly reduced in bison vaccinated with RB51 (1.2×10 10 –6.1×10 10 CFUs) when compared to unvaccinated controls (15% versus 62%) following conjunctival challenge with 3×10 7 CFUs 2308 (Olsen et al, 2003). Furthermore, revaccination of bison with RB51 did not cause abortion, but RB51 was recovered from tissue samples in 16.7% pregnant bison (Olsen and Holland, 2003). In a separate study, RB51 showed little efficacy in adult and calf bison despite repeated subcutaneous vaccinations with 1×10 7 –1×10 9 CFUs given as a primary immunization and boosted with 1×10 9 CFUs followed by a conjunctival challenge with 1×10 7 CFUs 2308 (Davis and Elzer, 2002).…”

Live RB51 vaccine lyophilized hydrogel formulations with increased shelf life for practical ballistic delivery

“…Strain RB51 has also been shown to be generally effective as a vaccine in bison, generating host immune response, protection and ultimately prevention of abortion at doses of $10 10 CFUs (Roffe et al, 1999;Elzer et al, 1998;Davis and Elzer, 2002;Olsen et al, 1997Olsen et al, , 1998Olsen and Holland, 2003). This strain also has the inherent diagnostic advantage of not producing antibodies that interfere with standard serological field tests for brucellosis, limiting false positives observed from vaccination in field surveillance.…”