The concern that SARS-CoV-2 could be spread by people without symptoms originally came from a single case report. It was alleged that an asymptomatic woman from China had spread the virus to 16 other contacts in Germany. Later reports showed that, at the time of contact, this woman was actually taking medication for flu-like symptoms, invalidating the evidence provided for the theory of asymptomatic transmission.

https://trialsitenews.com/are-asymptomatics-sick-until-proven-healthy/

As Dr Anthony Fauci of the US National Institute of Allergy and Infectious Diseases stated in March 2020:

“In all the history of respiratory-borne viruses of any type, asymptomatic transmission has never been the driver of outbreaks. The driver of outbreaks is always a symptomatic person”.