Eradication versus vaccination strategies to control infectious diseases--some lessons to be learned from terrestrial animals.

Abstract

In the pre-vaccine era, highly contagious and dangerous animal virus diseases had enormous socio-economic impacts on societies, and the only way of control was a vigorous stamping-out strategy. Diseases that were difficult to diagnose on clinical grounds could not be contained and often became endemic. Considerable progress in the control of viral infections of farm animals was made when their viral aetiology became known and means for the propagation of the infectious agents, first in animals and later in cell culture, were developed. This led to the development of several generations of vaccines that were applied with increasing success in the control of infectious diseases. Inactivated as well as live attenuated vaccines were successfully used, as shown in the control of classical swine fever and foot-and-mouth disease. Recently both inactivated and live "marker" vaccines have been added or will be added to the repertoire of tools for the control and eradication of infectious diseases. Attempts to eradicate endemic Aujeszky's disease from pig populations are greatly facilitated by the systematic use of deletion marker vaccines. Currently the use of marker vaccines for emergency use to contain outbreaks of classical swine fever and foot-and-mouth disease is under discussion between stakeholders and legislators.