A review of vaccine development and research for industry animals in Korea

Lee, Nak-Hyung; Lee, Jung-Ah; Park, Seung-Yong; Song, Chang-Seon; Choi, In-Soo; Lee, Joong-Bok

Brucellosis has been a major zoonotic disease threating humans and animals in developing countries. Brucella infections in livestock result in abortions, weak offspring and longterm fertility problems. In many developed countries, test and slaughter strategy has been effectively adapted for eradication of these diseases. Vaccination provides a considerable level of protection but limited outcome to prevent brucellosis. Thus far, attenuated live vaccine is the most successful, which is widely used for cattle. Recently, the vaccine based on the stable rough mutant B. abortus strain RB51 is used in many countries, including the US. Human infection usually occurs by consumption of unpasteurized milk. Since cellular immunity is required for a long-term protection, the best results have been obtained with live attenuated vaccines. The vaccine also works in herds of adult animals, but lower doses are used to prevent abortion and interference with serological diagnostic tests. More recently, the rough strain RB51 with reduced O-antigen expression was developed and has been used in the US since 1996. Generally speaking, none of the available Brucella vaccines give sterile protection. The best way to control brucellosis successfully is to use hygienic measures as well as spelling out a specific protocol in production. A research to vaccination against Brucella was conducted once in Korea but the vaccine strategy was abolished to continue the policy of the test and slaughter, which leads to lowering prevalence from 5% in early 2000 to 0.5% in 2012.