Bioweapon

A bioweapon, or biological agent, is a weaponized pathogen intended to cause disease in lifeforms. Biological weapons can be used in warfare or in terrorist acts to decimate large populations without having to engage in direct combat or destroy infrastructures. The United Nations Space Command general emergency code Hydra signifies imminent threat from biological weapons of mass destruction. The Office of Naval Intelligence had a bioweapons team.

History
After establishing a research facility on Trevelyan in March 2553, the Office of Naval Intelligence's bioweapons team began to experiment on genetically modifying the proteins and saccharides in the colo and the Sangheili grain known as irukan, with the goal of creating a bioweapon to be unleashed against the Sangheili as a backup plan in the event ONI's strategy to destabilize them failed.

On February 7, 2556, Sedra City on the planet Sedra was attacked by a Sangheili terrorist using a biological weapon that only affected humans. An Office of Naval Intelligence unit was forced to work together with the Sedran Colonial Guard to track down the origin of the element used to manufacture the bioweapon.

After the Human-Covenant War, a group of Kig-Yar occupied a Covenant research laboratory on the planet Ven III. They were killed by a biological agent in early May 2558. A lone Sangheili survived and fled the laboratory carrying the bioweapon in a containment cylinder. The UNSC was alerted and tasked the with investigating the Covenant bioweapon.

List of appearances

 * Halo: Ghosts of Onyx
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * The Mona Lisa
 * Halo: The Thursday War
 * Halo: Escalation
 * Halo: Nightfall
 * Halo 5: Guardians