There’s no test for long Covid. There’s no specific drug to take or exercises to do to ease its symptoms. There isn’t a consensus on what long Covid symptoms are, and some doctors even doubt that it’s real. Yet with vast numbers of people having had Covid-19, and estimates ranging from 7.7 million to 23 million long Covid patients in the US alone, researchers say it has the potential to be “the next public health disaster in the making.”