The virus came. Nobody knows its origins. Some claim it was created by scientists in some experimental lab somewhere in China. At first the virus just caused high fever. Unfortunately it was enough for seniors to kill them. Later the virus developed and caused massive wave of deaths. Governments tried everything they could to stop the spreading. But it was too late. Before the first vaccine was developed, 15% of world population died. Before the first vaccine successfully saved infected patient, another 10% of world population died. ...