COVID PCR tests were widely run at 40-45 cycle thresholds, despite experts warning that anything above 30-35 cycles was likely detecting dead viral fragments rather than active infection. There is no universal threshold for what constitutes a positive result — the Corman-Drosten paper that established the WHO-adopted test never defined positive vs. negative. On January 20, 2021, the day Biden took office, the WHO issued guidance warning that high cycle thresholds could produce biased results.