Modelling the effects of pre-exposure and post-exposure vaccines in tuberculosis control.
J Theor Biol
; 254(3): 633-49, 2008 Oct 07.
Article
in En
| MEDLINE
| ID: mdl-18644386
ABSTRACT
Epidemic control strategies alter the spread of the disease in the host population. In this paper, we describe and discuss mathematical models that can be used to explore the potential of pre-exposure and post-exposure vaccines currently under development in the control of tuberculosis. A model with bacille Calmette-Guerin (BCG) vaccination for the susceptibles and treatment for the infectives is first presented. The epidemic thresholds known as the basic reproduction numbers and equilibria for the models are determined and stabilities are investigated. The reproduction numbers for the models are compared to assess the impact of the vaccines currently under development. The centre manifold theory is used to show the existence of backward bifurcation when the associated reproduction number is less than unity and that the unique endemic equilibrium is locally asymptotically stable when the associated reproduction number is greater than unity. From the study we conclude that the pre-exposure vaccine currently under development coupled with chemoprophylaxis for the latently infected and treatment of infectives is more effective when compared to the post-exposure vaccine currently under development for the latently infected coupled with treatment of the infectives.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Tuberculosis
/
Tuberculosis Vaccines
/
Models, Biological
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J Theor Biol
Year:
2008
Document type:
Article
Affiliation country:
Zimbabwe