T-Veronica virus

The T-Veronica virus is the main virus used in Resident Evil Code: Veronica, and is responsible for the mutation of several enemies. There is also a variant strain of the virus named T-Alexia that is a diluted form of the virus created during its period of cryogenesis in its main host, Alexia Ashford.

According to the series timeline, the T-Veronica virus was created by Alexia Ashford through synthesis of the Progenitor virus and the gene of a queen ant that contained an "ancient virus". She administered it to her father, but because the infection was not controlled, he became unstable and mindless. This led her to discover that the mutations could be controlled if slowly absorbed during cryogenesis.

Like the Progenitor and T- viruses, the T-Veronica virus causes rapid mutation, but the infection can be controlled and intelligence can be retained if the virus is absorbed over a long period of time. Alexia Ashford achieved this by remaining in a cryogenic sleep for fifteen years while the virus merged with her at a cellular level. Among the mutations to Alexia caused by the virus were combustible blood and vomit, multiple tentacular muscles, and the ability to exert control over the hive mind of the ants the virus was extracted from.

Though the T-Veronica virus is a useful tool for transhumanism purposes, it is useless as a bio-weapon, as its infection rate is low and it can only be transferred through direct injection. Because she is able to mentally control any organism infected with T-Veronica, Alexia, rather than use the virus as a weapon, planned to use her infected ants to spread the virus around the world by biting and injecting humans and animals with the virus, giving her control of every creature on earth.