Newsnight S46 E237 'Mask up for flu wave'

How worried should we be by rising cases of the virulent H3N2 flu strain, as people with symptoms are told to wear a mask? We ask to a top virologist. Also, President Trump says he deserves 'A-plus-plus-plus-plus-plus' on the economy. So why are so many Americans feeling the pinch? With Nick Watt.