Vaccination against bubonic and pneumonic plague

Yersinia pestis is the etiological agent of bubonic and pneumonic plague, d iseases which have caused over 200 million human deaths in the past. Plague still occurs throughout the world today, though for reasons that are not f ully understood pandemics of disease do not develop from these outbreaks. A ntibiotic treatment of bubonic. plague is usually effective, but pneumonic plague is difficult to treat and even with antibiotic therapy death often r esults. A killed whole cell plague vaccine has been used in the past, but r ecent studies in animals have shown that this vaccine offers poor protectio n against pneumonic disease. A live attenuated vaccine is also available. W hilst this vaccine is effective, it retains some virulence and in most coun tries it is not considered to be suitable for use in humans. We review here work to develop improved sub-unit and live attenuated vaccines against pla gue. A sub-unit vaccine based on the F1- and V-antigens is highly effective against both bubonic and pneumonic plague, when tested in animal models of disease. This vaccine has been used to explore the utility of different in tranasal and oral delivery systems, based on the microencapsulation or Salm onella delivery of sub-units. (C) 2001 Elsevier Science Ltd. All rights res erved.