Background and Aim: Brucellosis is a zoonotic disease caused by the bacterium of the genus Brucella. This disease is present worldwide, especially in developing and underdeveloped countries, where it is endemic. This first-of-its-kind study in Lebanon aimed to assess the prevalence of brucellosis across the country and to determine the efficacy of a vaccine for reducing losses in herds so that its toll on public health is reduced.

Materials and Methods: Three hundred and fifty-three blood serum and 261 milk samples were obtained from cows in different areas of Lebanon. The samples were analyzed using serological tests (rose Bengal, milk ring, and indirect enzyme-linked immunosorbent assay [ELISA]) and confirmed with competitive ELISA and polymerase chain reaction.

Results: The highest rate of Brucellae was found in the Bekaa region (10%). After vaccination of 5 cows and 13 heifers at different times, the results showed that all the vaccinated animals have developed an immune response to brucellosis 60 days after vaccination. This vaccine can be considered as stable and preventative to protect against brucellosis in animals and thus protect the public from this infection.

Conclusion: These findings will provide further insight into designing future targeted awareness interventions and adapted policies as efforts toward reducing the prevalence and prevention of brucellosis in cattle in Lebanon.

Keywords: Brucella abortus and melitensis, brucellosis, public health, vaccines, zoonosis.