Complexity of an SIR epidemic dynamics model with impulsive vaccination control

This paper considered an IR epidemic model with impulsive vaccination, which may inherently oscillate. We studied the impulsive control and get the conditions on which epidemic-elimination solution is globally asymptotically and the conditions of boundedness of system. On the other hand if the epidemic is turn out to be endemic, we studied numerically the influences of impulsive vaccination on the periodic oscillation of the system which is without impulsion and found phenomenon of chaos in this case. (c) 2005 Elsevier Ltd. All rights reserved.