In Cinder, Levana uses the plague as both a political, social, and economic tool in order to decrease the population and, in turn, decrease the likelihood she will be overthrown. Levana’s ability to release an antidote is also a political and social tool which she anticipates will help codify and solidify her power as the world will feel as though she is a savior.
The reader also witnesses the political and social sacrifice of Prince Kai. He knows that marrying Levana is a death sentence for him, but it will help the rest of the world.
On a more personal level, the plague removes those that Cinder loves. Cinder is sold into the plague research initiative to have tests run on her. This socially deepens the divide between the humans and the cyborgs. It’s important to note that Cinder’s family economically benefits because they receive money from selling Cinder into the research initiative.
In order to connect the narrative to today’s social, political, and economic climate, it’s important to recognize the motivations behind political leaders. Political leaders are tasked with persevering and improving society, but often they are driven by economic purposes. Power has the ability to corrupt, so the decentralization of power is a worthwhile venture for societies.
The plague in the Eastern Commonwealth has caused social and political unrest. People are displeased that the Emperor hasn't been able to find a cure yet; when he dies, it makes things even more unstable. It also makes people distrust each other. People are all so scared of becoming ill that any sign of illness is met with distrust. Their already-present distrust of cyborgs is heightened when they get the opportunity to sell them for plague research.
For Cinder, the plague takes away people she loves. She loses her sister and is sold to the Emperor's plague research initiative as a test subject. She also comes to find out her true identity because of the plague research though.
For Cinder's family, they lose their youngest daughter and their sense of stability. However, they also benefit from the money they get when they sell Cinder.
For Kai, the plague has weakened his kingdom and put him in a position where he has to negotiate with Levana. He loses his father and ultimately loses control of his kingdom to her.
Levana kills those she can't brainwash because they can see the truth of her reign and might seek to overthrow her. It's important even in modern society to be aware of what's going on and to be sure you aren't getting a biased viewpoint. While people may not be killed for knowing what's going on, it's increasingly difficult to do in a partisan and polarized world. It's important to look at why laws and choices are being made to understand the purpose behind them, who they benefit, and whether they serve the common good.
The plague has personal ramifications for Cinder and her family because Peony becomes infected with the plague and dies from it. It is a massive blow to Cinder because Peony is the only family member that treats Cinder like an actual human being rather than a piece of property to be bought, sold, and abused.
This notion that Cinder is a piece of property functions as a major rising action, as Cinder's step-mother "volunteers" Cinder for medical testing against the plague. Cyborgs have always been treated as second class citizens, but the fact that non-cyborgs consider it morally acceptable to use cyborgs as medical test subjects really drives home how cyborgs are not given complete human rights. The plague escalates this social division.
Politically and socially, the plague is a weapon that Levana set upon Earth to diminish the population and make the nations of Earth more pliable to letting Levana take massive Earthly political powers in exchange for her antidote. This is how she is able to force Prince Kai into marrying her. He knows that he is likely to die once he is married to Levana; however, he knows that his actions will save millions of people. His death is worth the lives of many other people.
In Cinder, the plague, letumosis, is an epidemic for which there is no known cure. Because Prince Kai’s father, Emperor Rikan, has the plague, there is a national crisis in New Beijing. This alarms the neighbors because it will spread and destabilize the whole region. In a desperate search for the cure, cyborgs have been used for testing. When Cinder’s step-sister Peony contracts it, she is sent to quarantine and Cinder, who is part cyborg, is sent for testing. She soon learns that she is immune. Queen Levana intended to marry Kai in part to create an alliance with the Commonwealth, and Kai agrees for political reasons and because she gave him a plague antidote.
Through Dr. Erland, when Cinder learns she is Selene, she is confused about her origins and rather frightened of her responsibilities but he convinces her to embrace them. Prince Kai wanted Princess Selene, who is Queen Levana's niece, to occupy the Luna throne. Learning Cinder’s true identity, Kai broke off with Levana. Cinder is a threat because she has the knowledge and immunity, and is eligible to become the legitimate queen.
A rule to kill people who resist brainwashing is the worst kind of tyranny, However, Levana sees an advantage in that she knows Cinder/Selene cannot be brainwashed. Levana fears that Selene will take the throne, marry Kai, and eliminate her chances for political advancement.
Many possible parallels can be drawn to current society. Although most people are not princesses these days, Cinder’s circumstances in her step-family can be like those of many children living in abusive arrangements. When there are widespread social policies, such as killing those with independent minds, people unite in opposition and this can be a source of rebellion or building a democratic society, rather than monarchy.