This is what they were talking about, exposure __does not require__ you get sick. You can still be exposed, but you don't need to let the concentrations of pathogens to build up in stale air over the course of a school day.
The results aren't in yet, and of course will be subject to reproduction/duplicatation, but I suspect that's what we're seeing here. People (children) are still getting sick, just less so, presumably because they're getting exposed to lower concentrations of pathogens. The article doesn't make it clear (or I missed it) if the reduction is in severity (time spent recovering from being sick), frequency (number of times one gets sick), or a combination thereof. If I'm right, I'd expect it to be a reduction stemming from both reduced frequency/severity.
Most low-level infections probably go unnoticed, and won't show up in the study at all.
Some days the kids are just a bit off, and taking their temperature shows slightly elevated temperature (37.2°C in ear). I'm pretty sure they are fighting some mild infection, but they aren't really ill.
The results aren't in yet, and of course will be subject to reproduction/duplicatation, but I suspect that's what we're seeing here. People (children) are still getting sick, just less so, presumably because they're getting exposed to lower concentrations of pathogens. The article doesn't make it clear (or I missed it) if the reduction is in severity (time spent recovering from being sick), frequency (number of times one gets sick), or a combination thereof. If I'm right, I'd expect it to be a reduction stemming from both reduced frequency/severity.