The big difference between this and flu is that there is no effective drug and vaccine. Some people react mildly to the virus, some people's immune system seems

The big difference between this and flu is that there is no effective drug and vaccine. Some people react mildly to the virus, some people's immune system seems to compromised by the virus quickly. It also seems to have long incubation periods and high infection rate. In a city as dense as China, it would spread quick from person to person. So the only effective way to reduce infection is to quarantine people. Not allow them to gather around. Flu is actually affects a lot of people too. It just not a "massive event" because we dont try to contain it. It would take a similar measure to try to contain flu if there is no flu vaccine