You have to hand it to the influenza virus. For something that’s invisible to the human eye, it certainly has a way of grabbing our attention and anxiety–not just once in a blue moon but every year, winter after winter.
This season the potentially deadly virus is in rare form. Public-health experts are predicting that this year’s flu will be severe for several reasons. Cases are starting up early, which is one indicator of an aggressive virus. Another worry: Australia’s flu season typically augurs that of the U.S., and so far this year, Australia recorded 2½ times as many cases, compared to the same period last year.