Table 1 ToP values corresponding to varying levels of RT-PCR–confirmed symptomatic COVID-19 protection for the PROVENT ToP model

From: A SARS-CoV-2 variant‑adjusted threshold of protection model for monoclonal antibody pre-exposure prophylaxis against COVID-19

Efficacy threshold

Required nAb GMT

Converted to IU/mLa

40%

195

28

50%

458

65

60%

1297

185

70%

4959

708

  1. A time-varying Cox model was fit adjusting for treatment and its interaction with the prevalence-adjusted nAb ID50 titres. Efficacy was calculated as 100(1 – hazard ratio) (%). The nAb ID50 titres required to achieve the specified efficacy levels are presented here.
  2. COVID-19 coronavirus disease 2019, GMT geometric mean titre, ID50 50% inhibitory dilution, IU international units, nAb neutralising antibody, RT-PCR reverse transcription-polymerase chain reaction, ToP threshold of protection.
  3. aRequired nAb ID50 titres converted to IU/mL based on a conversion factor of 0.1428, which was developed using the Wuhan D614 variant.
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