How did the virus happen?

The story line behind the virus is that a company called Pandorax were creating a solution to prevent, if not stop, ageing.

The virus was the result of an anti-ageing drug that went wrong and once the virus started, it spread too rapidly before it could stop.

Symptons of the virus are headaches, body aches, wrinkly skin, greying hair and some lesions on the skin. Anyone displaying the symptoms would end up dead, only kids were immune to the virus. All the adults died.

There was an antidote for the virus, but it was unclear as to wether it worked and the virus had already spread before it could get distributed to the people who were dying from the virus.

However bearing all this in mind, the exact story about the virus remains a mystery. Some of the answers to how it was created and how it spread are given in series 2 of The Tribe.