Date Thesis Awarded


Access Type

Honors Thesis -- Access Restricted On-Campus Only

Degree Name

Bachelors of Science (BS)


Interdisciplinary Studies


Leah Shaw

Committee Members

Margaret Saha

Junping Shi


Poliovirus is a single-stranded RNA virus that causes poliomyelitis. Although vaccines exist, poliovirus is still not fully eradicated in areas with limited health resources. In addition, in recent years there are increasing cases of vaccination-derived strains of poliovirus. We model an alternative therapeutic strategy to assist the polio eradication through the usage of defective interfering particles (DIPs), a defective variant of wild-type (WT) virus lacking a protein capsid essential for viral replication. Co-infection of DIPs and WT forms a competitive relationship that decreases the overall viral load. Previous modeling through ordinary differential equations shows that viral load can be decreased through the introduction of DIPs, but a complete clearance of virus can not be achieved by DIPs alone. We introduce interferon as a representative of the immune system to examine the possibility of complete clearance. We analyze the basic reproduction number R0 in the presence of interferon and find that the introduction of DIPs is neither able to stabilize the DFE nor prevent the WT from invading the population. DIPs are found to be effective in terms of decreasing the steady state of WT only when interferon is weak or produced at low level. Assessment of effectiveness of DIPs under varied initial number of DIPs shows that increasing the initial number always decreases the time taken for WT to reach steady state. Assessment of effectiveness of DIPs under varied time in which DIPs are introduced shows that it can be better to add DIPs later instead of at the very beginning when IFN is strong.

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Creative Commons License
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