A Once-In-a-Century Pandemic?

Bill Gates, writing in the New England Journal of Medicine:

“In the past week, Covid-19 has started behaving a lot like the once-in-a-century pathogen we’ve been worried about. I hope it’s not that bad, but we should assume it will be until we know otherwise.”

“There are two reasons that Covid-19 is such a threat. First, it can kill healthy adults in addition to elderly people with existing health problems. The data so far suggest that the virus has a case fatality risk around 1%; this rate would make it many times more severe than typical seasonal influenza, putting it somewhere between the 1957 influenza pandemic (0.6%) and the 1918 influenza pandemic (2%).”

“Second, Covid-19 is transmitted quite efficiently. The average infected person spreads the disease to two or three others — an exponential rate of increase. There is also strong evidence that it can be transmitted by people who are just mildly ill or even presymptomatic.”