Plague of 1975

The Plague of 1975 is the decisive historical disaster of the novel: it kills or transforms most of humanity, creates the conditions of vampirism, and leaves Robert Neville isolated in a world whose surviving population no longer recognizes him as normal. Its significance lies not only in its death toll but in the way it turns superstition into epidemiology, private grief into public emergency, and emergency survival measures into the foundation of a new social order.

Emergence and Uncertainty

The plague first appears as an unexplained illness spreading through ordinary communities. Virginia Neville reports that half the people on the block have contracted it while more than half of the plant is absent, and Robert Neville can offer only the tentative explanation that it may be some kind of virus. Even after the disease has spread across the country, authorities have not identified the germ. The uncertainty makes the epidemic more than a medical problem: it becomes an atmosphere of rumor, absence, and mounting fear.

The disaster is linked, at least speculatively, to the wider disturbances of the period. When Virginia asks whether bombings may have caused the sudden changes occurring in people, the possibility is left open, alongside the suggestion that the upheavals may also be causing dust storms and other effects. The plague therefore enters the narrative as part of a compound crisis in which war, environmental disruption, and biological transformation are difficult to separate.

Spread and Public Response

The speed of the outbreak becomes one of the clues to its nature. Robert Neville reasons that the plague could not have advanced with such geometrical rapidity if it had been transmitted only by vampires during their nightly attacks. The eventual hypothesis is that flies and mosquitoes helped spread the disease, allowing infection to race through the world independently of direct encounters with vampire hosts. A medical text's account of insects mechanically disseminating bacterial diseases supplies a crucial support for this interpretation.

The epidemic also produces a secondary contagion of fear. During its final phase, sensational newspapers spread a nationwide campaign about vampires through pseudoscientific articles, while revivalism surges as people seek simple religious explanations for a catastrophe they cannot understand. The result is a feedback loop between disease and interpretation: infection kills people, fear supplies a supernatural vocabulary for the deaths, and that vocabulary obscures the physical agent responsible.

Public policy becomes correspondingly extreme. Funeral parlors close, healthy morticians are prevented from practicing, and every body must be taken immediately to the fires because only flames are believed capable of destroying the plague bacteria. Robert Neville understands the law but cannot accept its demand when Virginia dies. He hides her body beneath a blanket, sewing the covering over her mouth, nose, and eyes, because his personal vow that she will not be burned outweighs his submission to the emergency regime. Her subsequent return exposes the terrifying consequences of death, infection, and incomplete separation from the living.

Discovery of the Vampiris Bacillus

Robert Neville's investigation gradually replaces vampire legend with biological explanation. After studying bacterial material and the relation between sunlight and germs, he recognizes that bacteria could explain the plague's extraordinary speed. His decisive laboratory breakthrough comes when he places his thirty-seventh blood slide beneath the microscope and sees a moving germ. He identifies it as a bacillus and names it Vampiris.

The organism is described as a cylindrical bacterium propelled through the blood by hairlike flagella. Robert Neville's discovery changes the meaning of the vampire: the vampire is real, but the traditional story has mistaken the visible host and its frightening behavior for the underlying cause. The germ, rather than the prowling supernatural figure, is the villain hidden behind centuries of superstition.

His historical reasoning extends the discovery beyond the present catastrophe. He compares the fall of Athens to the Plague of 1975, arguing that the ancient disaster may likewise have been produced by the vampire infection rather than by bubonic plague as traditionally recorded. He also considers the Black Plague through the same lens. This does not erase the cultural history of vampires; it rewrites that history as the long human record of a pathogen repeatedly misidentified through legend.

Biological Mechanism and Human Consequences

Robert Neville later explains that the bacillus creates an isotonic solution in the blood, slows circulation, activates bodily functions, lives on fresh blood, and supplies energy. When fresh blood is unavailable, it either produces self-killing bacteriophages or forms spores. After the vampire host decomposes, the spores disperse, seek new hosts, germinate, and establish another infection. The disease thus combines active infection in a living host with a dormant phase capable of extending transmission after death.

The consequences are both physiological and social. The plague's victims become the basis of the vampire population, while the mandatory destruction of corpses reflects the authorities' attempt to interrupt bacterial communication and dispersal. The policy treats every dead body as a potential epidemiological danger, but its emotional cost is measured in spouses and children carried to bonfires. For Robert Neville, the law turns mourning into an act of forced participation in the catastrophe.

Eight months after the plague's last victim, Robert Neville has gone nine months without speaking to another human being, and Virginia has been dead for ten months. His continued survival is not presented as recovery or acceptance. He neglects food, drink, sleep, and bodily care, yet continues to maintain the defenses and supplies that make survival possible: a generator, freezer, electric stove, water tank, greenhouse, workbench, books, records, and stores of canned food. The plague has destroyed his future, but it has not extinguished the life force that keeps him constructing a precarious present.

New Society and Historical Reversal

The plague ultimately changes the definition of normality. The infected survivors who organize themselves into a new society are not merely remnants of the old world; they intend to rebuild society and eliminate those whom death has left in an altered state. Ruth explains that they are infected but have found a way to remain alive, and that they may decide to kill Robert Neville and others like him. The disease has therefore generated a political community whose members understand themselves as the future rather than as monsters.

That reversal is dramatized when dark-suited men methodically kill approximately seven visible vampires, including six men and one woman, by restraining them and driving pikes into their chests. Robert Neville watches the slaughter from his house and recoils from the perpetrators' triumphant, emotionless faces. Their violence resembles organized policing or gangster brutality rather than desperate improvisation, suggesting that the plague has not simply destroyed civilization; it has produced a new civilization with its own norms, classifications, and sanctioned executions.

The final irony is that Robert Neville's scientific success cannot restore the world that existed before the plague. By identifying the bacillus, he explains the vampire, but he also helps reveal why the new society must regard him as an obsolete remnant. The plague's deepest consequence is thus a change in historical perspective: the old humanity interprets the infected as monsters, while the infected majority interprets Robert Neville as the abnormal survivor. The epidemic does not merely end a society; it determines who will inherit the word normal.