Throughout history, mankind has repeatedly fallen victim to dreadful epidemics or pandemics that have claimed the lives of millions over the centuries; from the ‘plague of Justininan’ dating back to the Roman empire, via ‘the Black Death’ in the Middle Ages, to the ‘Spanish flu’ in 1918, the ‘Asian flu’ of 1957 and the ‘Hong Kong flu’ of 1968 (Zanetti and Zappa, 2010). By the 1970s it had become common to believe that infectious diseases were declining and would be soon eliminated through medical progress. This optimistic view appears to have been naive. In the past few decades, the world has been confronted with several (sometimes severe) infectious threats (Zanetti and Zappa, 2010). Scientists now agree that new viral strains will emerge and continue to puzzle scientists, presenting challenges to the public health of future societies (Cohen, 2000; Medina and Garcia-Sastre, 2011; Sassetti and Rubin, 2007).