Fig. 3: Comparison of the N-antibody trajectory-based classification, fixed 30 ng/mL classification, fourfold-based classification and fourfold-based sensitivity analysis across different data sources used to define swab-positive infections.

a Percentage of participants with N-antibody (hypothetical) infections that were identified using swab-positivity (b) Percentage of participants without N-antibody (hypothetical) infections with no positive swab. In Fig. 3b the four lines (nearly) overlap. Survey: only using positive and negative swab PCR test results from the COVID-19 Infection Survey to define swab-positive infections; NTP: using positive PCR and LFT swab test results from national testing programmes in England and Wales; Self: using self-reported positive swab test results; Think: using self-report on thinking one had had COVID-19.