The earliest scientific article (to the best of my knowledge) that reported on the possibility there was asymptomatic transmission of COVID was a case study published ⭐February 19⭐, 2020, in the scientific research journal The Lancet Infectious Diseases:
Pan X, Chen D, et al. (2020) "Asymptomatic cases in a family cluster with SARS-CoV-2 infection"
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30114-6/fulltext
This was very quickly followed by another case study, published ⭐February 21⭐, 2020, in the Journal of the American Medical Association (JAMA, a very high-prestige medical research journal):
Bai, Y, Yao, L, et al. (2020)
"Presumed Asymptomatic Carrier Transmission of COVID-19"
https://jamanetwork.com/journals/jama/fullarticle/2762028
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