“…if a person gets a “positive” PCR test result at a cycle threshold of 35 or higher (as applied in most US labs and many European labs), the chance that the person is infectious is less than 3%. The chance that the person received a “false positive” result is 97% or higher.”

The Trouble with PCR Tests. Swiss Policy Research. October 2020. https://swprs.org/the-trouble-with-pcr-tests/