The Brucella melitensis M5-90ΔmanB live vaccine candidate is safer than M5-90 and confers protection against wild-type challenge in BALB/c mice.

Brucellosis is a globally distributed zoonotic disease that causes animal and human diseases. Although effective, the current Brucella vaccines (strain M5-90 or others) have several drawbacks. The first is their residual virulence for animals and humans and the second is their inability to differentiate natural infection from that caused by vaccination.