April 23, 2020 / By Denise Chow
New York Gov. Andrew Cuomo on Thursday offered what appeared to be a surprising statistic on just how broadly the outbreak of the coronavirus has hit the state: Almost 14 percent of people tested in a new study were found to have antibodies to the disease it causes.
It might be good news. The data suggest that the state’s mortality rate could be lower than previously thought, albeit much higher than for seasonal influenza. But it’s still too early to reach that conclusion — or any other extrapolations people might want to make about easing lockdowns, experts say. 
Beyond that data point, Cuomo’s presentation offered little detail that would allow a full assessment of whether that many New Yorkers really were infected. The numbers were from a preliminary analysis of a study that wasn’t released publicly, so most of its methodology remains unknown. The state Health Department didn’t respond to a request for a copy of the study.
That doesn’t mean the findings are wrong. But it does mean that extreme conclusions about the mortality rate or the state’s ability to reopen shouldn’t be drawn from the data.
“There’s a risk of really serious misinterpretation here,” said William Hanage, an associate professor of epidemiology at Harvard University’s T.H. Chan School of Public Health in Boston. “But the most basic conclusion — that quite a large number of people may have been infected and are not turning up in the official case counts — that’s extremely plausible and something we have been suspecting all along.”