News that H5N1 avian influenza has breached another mammalian species — this time dairy cows — has taken the flu science community aback. Though cows previously had been seen to be susceptible to human flu viruses, and could be experimentally infected with H5 in a lab, the absence of cow involvement until now in H5’s nearly 30-year history lulled scientists into thinking the species was outside the virus’s remit.
Further elevating the concern this discovery has triggered is the fact that a dairy farm worker in Texas was infected with H5N1, though the unnamed individual’s only symptom was conjunctivitis. To put these developments in perspective, STAT turned to Dutch virologist Ron Fouchier, a leading expert on H5N1, for his assessment of these latest twists in the H5 saga. Fouchier, who studies avian influenza at the Erasmus Medical Center in Rotterdam, was at the center of a controversy about H5N1 in 2012, when a U.S. scientific advisory group moved to restrict publication of research he and a team at the University of Wisconsin-Madison had done — separately — to see what mutations would be needed for the virus to be able to spread efficiently among people, so-called gain of function research.