Survival of Brucella abortus Strain RB51 Lyophilized and as Liquid Vaccine under Different Storage Conditions

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

“…6) at 4 C. LHPs intended for vaccine delivery contained at least 1.6 Â 10 10 CFUs of RB51 after this period, so a 61% loss in viability is acceptable for storing LHPs for up to 90 days to retain the desired $10 10 CFUs/dose. This reduced viability is significantly greater than previous lyophilized RB51 formulations demonstrating retention of 74-93% of initial viability when stored at À25 C, and 36-52% of initial viability stored at 4 C for 52 weeks (Capsel et al, 2000). LHP storage at À20 C did not significantly alter this loss in viability at 90 days, but did at longer time points (300 days) (Fig.…”

“…Lyophilized B. abortus live vaccine strain RB51 product was produced at the USDA facility in (Ames, USA) using previously established methods (Capsel et al, 2000).…”

“…Spontaneous PGD polymerization in the presence of commercial RB51 formulations is not observed since the commercial vaccine formulations as supplied contain unspecified proprietary preservatives (Colorado Serum Company technical literature), presumably also antioxidants that inhibit polymerization without exogenous initiators. Purified noncommercial RB51 and other bacterial inoculates lacking preservatives facilitate this limited polymerization observed (Capsel et al, 2000).…”

“…Bacterial viability decreased to 70.5% (AE2.1%) of initial viability after polymerization with the thermal initiator and to 44.4% (AE11.5%) of initial viability after lyophilization. RB51 viability is maintained during lyophilization by the presence of lactose salt media (Capsel et al, 2000). This was deemed an acceptable loss as sufficient viable organisms (>10 10 CFU per rod) remain for targeted vaccination dosing.…”