Over The Horizon

International Spotlight on Tuberculosis

With a global emergency declared for human tuberculosis and a range of countries facing difficulties in the control of animal tuberculosis where wildlife are involved, the World Health Organisation is taking a prominent role in efforts to develop improved Tb vaccines for both animals and people.

WHO recently convened a technical consultation at its headquarters in Switzerland to coordinate international efforts to develop suitable vaccines. Thirty invited scientists from around the world took part in the three-day meeting, which was chaired by Roger Morris from Massey University's Department of Veterinary Clinical Sciences.

"The best hope for the short term lies in adapting the human Tb vaccine, BCG, for use in animals, which is not as surprising as it seems, since it came from a bovine Tb strain to begin with," Morris says.

"Earlier efforts to use it in animals had been disappointing, but new technology and research results mean that this approach is now considered to offer hope of a vaccine earlier than other alternatives, and testing would be simpler than for novel approaches."

Morris notes that results of research at AgResearch Wallaceville have been crucial in showing that BCG has considerable promise, and further work is justified.

"There is potential for the use of vaccines based on BCG in both possums and domestic stock, although a lot remains to be done before a vaccine could be used in the field," he says.

"Surprising though it may seem at first, a possum vaccine would be easiest to produce and could well have a major impact on the disease in New Zealand livestock."

The consultation seminar concluded that wildlife vaccines are considered to have considerable value in protecting domestic stock, and various options were considered for vaccinating wildlife. Workers on human Tb could see great value in collaboration between veterinary and medical groups, and new methods of achieving such collaboration within WHO activities have been under discussion since the meeting.