In 1918, a highly virulent form of the influenza virus killed at least 20 million people worldwide. Understanding the origin of the virus that caused this pandemic has been a long-standing goal because of the risk that a similar virus could arise and devastate human populations today.

Influenza is an acute viral infection of the respiratory tract which is considered to be one of the life-threatening infectious diseases. In certain countries, seasonal influenza affects up to 40% of the population every year, with the worldwide death toll of 500 million people. The virus can be transmitted by direct contact with infected individuals, via contaminated objects (also called fomites) and by inhalation of virus-laden aerosols

Much like birds fly in flocks to conserve energy and ants create complex nests to protect their queens, immune cells engage in coordinated behavior to wipe out viruses like the flu.