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The New Plague virus,[1] also called the Blue Flu[2], or Limit 115[3] was an infectious disease which rapidly spread throughout the United States in the 2050s, eventually demanding a national quarantine in 2053.[4] The epidemic became the driving force behind the Pan-Immunity Virion project that paved the way for the Forced Evolutionary Virus.


Gray paragraphs are based on Van Buren and were not confirmed by primary sources The time of incubation of the virus varies, taking between three to five days. Initial symptoms greatly resemble the classic flu.[2][4] The Plague eventually worsens, leading to profuse sweating, unexplained contusions and swelling, eventually terminating in massive external hemorrhaging.[5] Gray paragraphs are based on Van Buren and were not confirmed by primary sources It may also result in clogged respiration, leading to death through asphyxia. Should anyone survive the plague, they are rendered completely sterile by the virus.[2][4]

Though the exact method of infection is unknown, the New Plague virus was highly virulent and could be easily contracted in any social situation. The usual methods of controlling the spread of the disease were isolation and containment.[6]


Gray paragraphs are based on Van Buren and were not confirmed by primary sources The New Plague virus was actually a top secret military project, codenamed Limit 115. It was a genetically engineered biological weapon developed by United States scientists working under the aegis of the power groups that would later form the Enclave. The intent was to deploy it against China, to sterilize large segments of the population and undermine enemy manpower.[7]

The virus was inadvertently released in 2053, when a group of Chinese infiltrators procured samples of the virus. They were killed in Denver during their escape and the sample containers were damaged. As they were shot in a public area, the virus managed to infect a large number of people.[7] This led to a widespread epidemic that killed an estimated twenty thousand citizens across the United States, with the epicenter in Denver, Boulder, and Colorado Springs.[2][4]

The virulent nature of the plague and the speed at which it spread led to the first-ever national quarantine of the nation and the closing of borders, as tens of thousands die.[8] In 2055, West-Tek started to develop a cure for the virus, establishing the West Tek Research Facility.[1]

However, despite extensive quarantine measures and research, no cure would be developed. By 2063, the New Plague continued to spread throughout the nation, the death toll fueling national paranoia.[8] The government used the rising paranoia to discourage assemblies, fuel the anti-communist sentiment, and encourage informing government forces of suspected subversive elements.[5]

West-Tek was ultimately unable to develop a cure. Instead, in 2073 the government contracted the company to develop a Pan-Immunity Virion in response to China's aggressive use of biological weapons. Although unsuccessful, the PV Project would lay the groundwork for the development of FEV.[8]

However, the FEV research would leak out in 2077, leading to widespread protests and lead many to speculate that the U.S. government was responsible for the New Plague in the first place.[8]

Behind the scenes

The plot of Van Buren centered around Victor Presper, an NCR scientist, who uncovered the truth behind the virus around the 2250s. He decided to use the potent virus as an agent to cleanse the wastelands and impose his order on the world. He would manipulate ULYSSES into activating B.O.M.B.-001 by releasing Limit 115 in survivor communities, forcing the AI to go into disease control mode (with nuclear weapons). By that time, Presper would be on board the space station and target the nuclear missiles where he wanted them to go.[9]


  1. 1.0 1.1 The Vault Dweller: "{112}{}{Tell me about this installation.}"
    ZAX 1.2: "{117}{}{This installation was established in 2055 as a biological research facility for experimental cures of the New Plague. However, in 2071, this facility was placed under United States military command.}"
    ZAX 1.2: "{118}{}{Research into possible cures for the New Plague created the Forced Evolution Virus, which was further developed in an attempt to create a transmittable genetic-engineering virus -- in effect, infectious evolution.}"
  2. 2.0 2.1 2.2 2.3 Van BurenGametitle-VB.png Boulder design document/2 Boulder design document/3 for Van Buren Van BurenGametitle-VB.png
  3. Van BurenGametitle-VB.png Hoover Dam design document/5 B.O.M.B.-001 design document/2 Hoover Dam design document/2 Van BurenGametitle-VB.png
  4. 4.0 4.1 4.2 4.3 Van BurenGametitle-VB.png The Prisoner: "{200}{}{PC: What is the New Plague?}"
    ZAX: "{201}{}{"Discovered in 2053, the New Plague was a socially transmitted plague that killed an approximately twenty thousand human beings in the United States, including cities such as Denver, Colorado, Boulder, Colorado, and Colorado Springs. The time of death from identification of symptoms was three to five days. Symptoms included many symptoms in common with the flu or chest cold, and eventually resulted in clogged respiration, killing the infected subject."}
    {202}{}{"The discovery of the New Plague resulted in the 2053 quarantine, and several emergency programs were established to find a cure for the plague. The Boulder Dome has limited information on the New Plague, since it was not one of the research concerns in the Boulder Dome. If you could find a medical research database concerned with the New Plague, or provide me with holodisks related to the New Plague, I could provide you with more information."}
    {203}{}{ "The only way we could fight off the New Plague was by creating better humans."}"
    (ZAX in Boulder dialogue pieces) Van BurenGametitle-VB.png
  5. 5.0 5.1 Disaster relief outpost terminals; Terminal, Know the Signs!: "Safeguard yourself and your community by knowing how to identify a person suffering from the New Plague. Common symptoms include:
    Profuse Sweating
    Unexplained Contusions/Swelling
    Massive External Hemorrhaging
    New Ideals, such as socialism"
  6. Disaster relief outpost terminals; Terminal, Remember to C.I.R.
  7. 7.0 7.1 Information acquired by Paweł "Ausir" Dembowski from J.E. Sawyer
  8. 8.0 8.1 8.2 8.3 Fallout Bible 0 Timeline repair: Second strike:
    "2053 The socially transmitted "New Plague" arises, killing tens of thousands. The United States closes its borders and the first-ever national quarantine is declared. The source of the plague is unknown, but rumors persist that it is a genetically engineered weapon."
    "2062 Despite quarantine measures, the New Plague continues to spread, fueling national paranoia."
    "2073 Sept 15 As China becomes increasingly aggressive with their use of biological weapons, the United States government felt that a countermeasure was needed. The Pan-Immunity Virion Project (PVP) is officially formed and plans are made to begin experiments at the West Tek research facility in Southern California."
    "2077 February FEV Research is leaked to the world through an unknown source. Protests in many major cities and governments around the world, as well as accusations that the US was responsible for the New Plague. FEV is seen as the threat it is, and serves only to fuel tensions."
  9. Van BurenGametitle-VB.png B.O.M.B.-001 design document for Van Buren Van BurenGametitle-VB.png