Why Does Natural Immunity Not Exist For the QCovid Risk Calculator?

There follows a guest post by a Daily Sceptic reader, who wishes to remain anonymous, who has some questions about the changing risk estimates being produced by the QCovid risk calculator and why important factors like previous infection are not taken into account.

The QCovid risk calculator was developed by University of Oxford, commissioned in 2020 by the Chief Medical Officer for England on behalf of the U.K. Government, and describes itself as a “clinical decision tool intended to support conversations between clinically trained professionals and patients about COVID-19 risk”. There is a clinician tool and a patient tool; the clinician tool differs only in some of the questions but delivers the same estimates.

I am a 49 year-old female with no pre-existing health conditions of note and am not obese. My daughter is a 19 year-old female with no pre-existing health conditions of note and is not obese. We ran the QCovid risk calculator in summer 2020 when considering the risk posed to ourselves and therefore the potential benefit of a vaccine.  My risk of dying was one in 62,000 or 0.0016% and my risk of hospitalisation was one in 4,000 or 0.025%. My daughter’s risk of dying was one in 500,000 or 0.0002%. This data must have related to the variants around at the time although the risk calculator never made that clear.  

I checked the risk calculator again multiple times over the past 18 months and it had not changed (or possibly was not updated).  

I checked again on January 11th 2022 and the calculator has changed. The questions are the same, but the data generated is different. 

  1. You can now select whether or not you are vaccinated – however it doesn’t ask which vaccine you might have had, or indeed when it was delivered. We now know this makes a difference. It also doesn’t make any reference to the number of doses. This also makes a difference.
  2. The risk assessment doesn’t delineate between variants and we know Omicron is significantly less harmful than Delta or Alpha.  Are they suggesting the risk posed to my health is equivalent?

I have a BSc in medical biochemistry and a Masters in law; I am analytical and data driven – I spend my days reviewing data, searching for patterns and loopholes. I am not a mathematician, but something about the data the calculator is now offering doesn’t feel right. The estimates provided by QCovid for both people (mother and daughter) are below, vaccinated and unvaccinated:


  1. By their own data I am less likely to contract coronavirus and die than I was before, whether vaccinated or not (line ii).
  2. However I am also more likely to catch coronavirus and be hospitalised if unvaccinated now than I was before (line i).
  3. There’s a new line in the data showing the risk of dying after a positive test – this can only be included to demonstrate the relative difference between vaccinated and unvaccinated, as the absolute risk differences in the other lines are so small (line iii).
  4. This table of results may look very different when considering Omicron with higher transmissibility, less effective vaccine, but lower virulence.
  5. My daughters risk of catching and dying of Covid is no different whether vaccinated or not (line v).
  6. My daughter’s risk of catching coronavirus and then being hospitalised is the same as mine despite our age difference.
  7. There’s no reference to the impact of prior infection or treatment protocols. Prior infection will dramatically reduce a person’s risk from Covid.

I suggest that the above data and the inclusion of lines (iii) and (vi) has been included to encourage people to get vaccinated, yet there is important data missing. It would be interesting if a mathematician or statistics analyst could review the QCovid risk calculator, assumptions and algorithm and draw attention to the misinformation and lack of transparency that is being used to influence vaccination uptake in private and clinical settings.

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