A study published November 20, 2020 of a city-wide, 19 day, mass PCR screening programme of nearly 10 million residents in Wuhan, China in the post-lockdown period from May 14, 2020 (Alpha variant), shows there “were no positive tests amongst 1,174 close contacts of [the 300] asymptomatic cases.”
Meaning those who have no symptoms but return a positive PCR result (asymptomatic) did not spread virus to close contacts.
Wuhan was under strict lockdown measures from January 23, 2020 until April 8, 2020. Lockdown was used to stop the virus spread, but mostly because “on of China’s top expert” there were “super spreaders“. Following lockdown, “the COVID-19 epidemic was generally under control in China, and the whole country has progressed into a post-lockdown phase.”
A systematic review published December 2020 showed asymptomatic spread was not a driver of the pandemic. [2]
In May 2022 published a systematic review of nearly 30,000 people over 42 countries has found asymptomatic carriers are about 68% less likely to pass the virus on compared to those with symptoms. [1]
The “symptoms” that can be classified as COVID-19 have undergone several changes over the course of the pandemic, initially being “a high temperature, a cough and a loss of taste or smell, but then simply feeling tired and a headache were added. So a healthy person with a headache that returns a [false] positive PCR result can be labelled “statistically sick” with COVID-19 i.e. a “case”. The more you “tests” the more “cases” will be found.
The risk of asymptomatic spread of SARS-CoV-2 was/is the reason governments around the world pushed for the testing and lockdown of healthy people. Quarantine of the sick has traditionally been the public health measure.