Yup, that's the research I was thinking of. Note that the transmission did occur, admittedly at a fairly low level. China is full of buildings with many, many

Yup, that's the research I was thinking of. Note that the transmission did occur, admittedly at a fairly low level. China is full of buildings with many, many residents and far from airtight. Many buildings over there also do not use p-traps. SARS has been documented to spread through the sewer stack this way, Omicron spreads *far* better than SARS.