Actual Coronavirus Infections Far Higher Than Confirmed Cases, Model Shows : Shots - Health News : NPR

...It estimates how many people are never counted because they never get tested. And it answers a second question that is arguably even more crucial — but that until now has not been reliably estimated: On any given day, what is the total number of people who are actively infectious? This includes those who may have been infected on previous days but are still shedding virus and capable of spreading disease...

https://www.npr.org/sections/health-shots/2021/02/06/964527835/why-the-pandemic-is-10-times-worse-than-you-think

Antibody Study Shows COVID-19 Rate of Infection May Be up to 85 Times Higher Than Reported

A study in a county in California suggests that the prevalence of people infected with the coronavirus is much higher than previously thought, potentially complicating decisions on whether to end widespread lockdowns.
https://www.newsweek.com/covid-19-coronavirus-antibodies-infection-higher-1498740