Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Paradox Of Vaccination Predicted By Simple Dengue Disease Model

we consider here two types of vaccination in a host-vector transmission model for a dengue fever decease. we assume that the vaccine prevents vaccinated people from cathing the desease caused bt all types of dengue viruses but it is not perfcet in which the vaccinated host may still suffer from the desease with a certain probability. The first type of vaccination is being administered constantly to a portion of newborn host. in this case the basic reproductive number remains the same and the vaccine will affect the eventual stages both for the desease-free equilibrium and epidemic equilibrium. the second type of vaccination which is administered to general population is more complicated. in the case that the target people can be restricted to susceptible host, the vaccination directly affec the basic reprpductive number, on the other hand, knowing that there is no practical way that infected people can be easily identified in teh field, there is a chance that infected people may get veccinatef unintentionally. in this case the unintenden vaccinated infected individual may stay longger in the ionfection stage. assuyme taht the vaccine affect are removeal rate from infection stage with a certain retaining rate. we found a somewhat paradox results whisg reveakls that increasing the portion of vaccinated individuals will lad to the increase of the basic reproductive number, if the retaining rate of mistalenly vaccinated people is sufficiently larger than the effectiveness of the vaccine. here we obtain the corresponding treshold number.