Invisible Killers: Season 1, Episode 1

1 - 1: Influenza

Influenza delves into the astonishing and little-understood history and impact of this constantly evolving virus, which is often tragically underestimated as merely a cousin to the common cold. Each year, six months in advance of the anticipated flu season, world health officials gather to speculate what strain of virus will be most prevalent and determine which vaccine will be most successful in treating those affected.