“Children might be more likely to be asymptomatic carriers of COVID-19 than are adults…This apparent lack of transmission [in schools] is consistent with recent research (5), which found an asymptomatic attack rate of only 0.7% within households and a lower rate of transmission from children than from adults. However, this study was unable to rule out asymptomatic transmission within the school setting because surveillance testing was not conducted” (emphasis added).
The “recent research” the study authors cite is a meta-analysis of 54 household COVID-19 transmission studies that observed 77,758 participants, which was posted as a pre-print this summer and published in December.
The text of the analysis is even more consequential than the CDC’s reference makes it seem: “Estimated mean household secondary attack rate from symptomatic index cases (18.0%; 95% CI, 14.2%-22.1%) was significantly higher than from asymptomatic or presymptomatic index cases (0.7%; 95% CI, 0%-4.9%; P < .001), although there were few studies in the latter group. These findings are consistent with other household studies28,70 reporting asymptomatic index cases as having limited role in household transmission” (emphasis added).
The 0.7 percent figure includes not just people who never show symptoms of COVID-19, but people who haven’t yet shown symptoms—two groups that have been alleged to be major factors driving the spread of the virus. This is a major data point often underplayed or even challenged in much media coverage of the virus.