Early PCR testing for COVID-19 yielded high rates of false positives due to the number of amplification cycles used.

Nov 7, 2026

Previously: Early PCR testing for COVID-19 yielded high rates of false positives due to the number of amplification cycles used. [Distorted]: This is a different claim from an earlier 80% figure, so it was checked fresh. High cycle counts did flag many positives with tiny amounts of virus, often people who were recovering, so some positives did not mean someone was contagious. But true false positives, meaning a positive with no virus at all, were very rare: the UK's national infection survey estimated its PCR specificity at 99.995% or better in 2020. A large dataset showing that most early positives had no viral RNA at all would make this verdict wrong.

Now: Early PCR testing for COVID-19 yielded high rates of false positives due to the number of amplification cycles used. [Distorted]: Rogan conflates high-cycle RNA detection with false-positive infection tests. ONS reported very high specificity for its controlled survey; CDC's panel used controls and a threshold below 40 cycles. A positive RNA test need not mean infectious virus, but that is different from no infection. A false-positive fraction also depends on prevalence and cannot be inferred from cycle count alone. This does not certify every laboratory's performance.

Keep the diagnostic distinction and avoid extrapolating one survey's assay performance to all early testing.