• Journal: Doctoral Dissertation
  • Date: Aug. 1, 2018
  • Category: Scientific Research


Nazila Akhavan Kharazian at Queens University reviewed the VSIR model of vaccine failure and attempted to use linearization methods in ecology to characterize when and which models can display honeymoon periods. This study uses Project Tycho pertussis data to show an example of a "honeymoon period" after the initiation of a mass vaccination program. The results of this study indicate that honeymoon periods need to be studied using non-linear techniques.


Nazila Akhavan Kharazian

Related Project Tycho Datasets

United States of America - Pertussis


Vaccination is a common method for protecting newborns from some childhood diseases like measles, mumps, and rubella. This control measure has proven to be very successful as evidenced by large decreases in the incidence of these diseases after the start of mass vaccination programs. However, the control of some diseases, such as pertussis, has recently become more difficult in some countries with high vaccination coverage. Mathematical models can be used to help understand the ramifications of different types of imperfect vaccines on post-vaccination disease dynamics and to harness this understanding to develop more efficient vaccination strategies. In this project, we review the VSIR compartmental model analyzed in (Magpantay et al., 2014) where people can be classified into one of four states: vaccinated (V), susceptible (S), infected (I), and recovered (R). This model allows for a vaccine that can exhibit different types of vaccine failures: in degree (leakiness), in take (all-or-nothing) and in duration (waning of vaccine-derived immunity). We also review existing methods in ecology for characterizing transient dynamics of disease systems such as the honeymoon period after start of mass vaccination programs.

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