Raphael ThysHow many people have really been infected by the coronavirus? In one German town a preliminary answer is in: about 14%.
The municipality of Gangelt, near the border with the Netherlands, was hard hit by covid-19 after a February carnival celebration drew thousands to the town, turning it into an accidental petri dish.
More on coronavirus
Our most essential coverage of covid-19 is free, including: What is herd immunity? What is serological testing? How does the coronavirus work? What are the potential treatments? Which drugs work best? What's the right way to do social distancing? Other frequently asked questions about coronavirus --- Newsletter: Coronavirus Tech Report Zoom show: Radio CoronaSee also: All our covid-19 coverage The covid-19 special issuePlease click here to subscribe and support our non-profit journalism.
Now, after searching blood from 500 residents for antibodies to the virus, scientists at a nearby university say they have determined that one in seven have been infected and are therefore “immune.” Some of those people would have had no symptoms at all.
Their brief report (PDF), posted online in German, has big implications for how soon that town, and the rest of the world, can come out from lockdown.
“To me it looks like we don’t yet have a large fraction of the population exposed,” says Nicholas Christakis, a doctor and social science researcher at Yale University. “They had carnivals and festivals, but only 14% are positive. That means there is a lot more to go even in a hard-hit part of Germany.”
Here's why the true infection rate in a region matters: the bigger it is, the less pain still lies ahead. Eventually, when enough people are immune—maybe half to three-quarters of us—the virus won’t be able to spread further, a concept called herd immunity.
But the German town isn’t close to that threshold yet, and to Christakis the preliminary figure is “unfortunate” because it means the virus still has more damage to do.