fowkes: yup. >> cooper: that's a stroke? >> dr. fowkes: that's a stroke. >> cooper: dr.ients may have been the sickest of the sick, but her work might offer clues for mount sinai researchers who are collaborating with colleagues around the world to figure out what's causing symptoms in living long-haulers. >> dr. mccarthy: i'll see you in six weeks, okay? >> cooper: dr. dayna mccarthy hopes her patients won't have to wait for answers. >> dr. mccarthy: we have the expectation of patients getting better. why? because there's nothing to say that they won't, yet. >> cooper: have any of your patients made a full recovery? >> dr. mccarthy: not full. i have some that are around 90%, 95%. >> cooper: but as new infections keep rising, so do the numbers of long-haulers. >> dr. mccarthy: there's thousands and thousands of people that are going through this. the numbers are enormous. and that's why it's so impactful. >> cooper: impactful not only on people's lives, on the economy, on-- >> dr. mccarthy: correct. on the healthcare system. how about-- >> cooper: on families. >> dr. mcc