So, 2m isn’t enough. 4.6 metres may still be risky. Good to know
It's quite a lot more subtle than that. It's all about air flow. This is a good read: zeynep.substack.com/p/small-data-big-implications
First see:
If you just want the results: one person (Case B) infected two other people (case A and C) from a distance away of 6.5 meters (~21 feet) and 4.8m (~15 feet). Case B and case A overlapped for just five minutes at quite a distance away. These people were well beyond the current 6 feet / 2 meter guidelines of CDC and much further than the current 3 feet / one meter distance advocated by the WHO. And they still transmitted the virus.
and then:
On the other hand, notice the striking number of people not infected in the study, despite sometimes being seated next to the initial infection case. People sitting in the same table as A1 were not infected. People sitting the next table over who had their backs to the airflow were not infected, even though two others in the direction of the airflow were. In other words, not facing the infected person mattered greatly. People sitting the same distance away from the index case but on the other side of the airflow, tables E and F, were completely spared. They were spared despite three out of four people in table B, where the air flew back again at them, getting infected, even though, like the unaffected table, were just a single table over.
You really can't just guess when it comes to these things. This is why I say the important thing is to count how many teachers have in fact been infected and find a suitable group to compare it with.