This paper analyzes specific incidents in which a group of one infected person plus some uninfected people sat down together, and some uninfected people got it. They find a secondary attack rate (from mostly non-household interactions) of 35%.
There are two big issues that prevent this paper from being used to draw good inferences about the household secondary attack rate. First, the incidents were found by specifically looking for superspreading events, and does not include any events where transmission didn’t happen. And second, the events are single gatherings, whereas living with someone may involve many opportunities to get infected.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30462-1/fulltext
This paper analyzes specific incidents in which a group of one infected person plus some uninfected people sat down together, and some uninfected people got it. They find a secondary attack rate (from mostly non-household interactions) of 35%.
There are two big issues that prevent this paper from being used to draw good inferences about the household secondary attack rate. First, the incidents were found by specifically looking for superspreading events, and does not include any events where transmission didn’t happen. And second, the events are single gatherings, whereas living with someone may involve many opportunities to get infected.