Alpha-Omega (Chinese: 阿尔法欧米茄 Ā'ěrfǎ ōumǐjiā) also known under the symbols α-Ω, is a deadly bioweapon. It was created by BTHK Biotech in Hong Kong. It consists of two corresponding parts: Alpha and Omega. General Matthew Shrieve used it to cause an outbreak in Hong Kong. Later, the weapon fell into Ra's al Ghul's hands, courtesy of Maseo Yamashiro. While preparing for Oliver Queen to become his heir, Ra's al Ghul attempted to have Starling City, Oliver's home, destroyed with the virus, but this attack was thwarted by Team Arrow.
After getting both the Alpha and Omega components of the virus, General Shrieve mixed the two substances and planned to cause an outbreak in Hong Kong. Oliver Queen, Maseo Yamashiro and Tatsu Yamashiro tried to retrieve the bioweapon but they found out it was just for a distraction. When Oliver tried to retrieve the virus from the Hong Kong marketplace the bioweapon fell on the ground and shattered, creating a huge viral outbreak. Many people died, including Maseo and Tatsu's son, Akio Yamashiro.
While Oliver Queen was infiltrating the League, he pretended to kill John Diggle, Felicity Smoak, Laurel Lance, Ray Palmer and Malcolm Merlyn with a sample of the Alpha-Omega virus. Unbeknownst to the group, Malcolm had inoculated them against the virus beforehand using a compressible skin graft.
Ra's had Oliver unleash the Alpha-Omega virus on Starling City as the latter's final ascension to Ra's al Ghul. When Oliver tried to resist, Ra's escaped with the virus and unleashed the Alpha-Omega on Starling City. However, Team Arrow was able to contain the outbreak while those infected were cured by Palmer Technologies through Ray's nanotechnology.
- Akio Yamashiro
- Hundreds of unnamed individuals