Absolute Risk Reduction (ARR) Calculation

In this 30min interview, Dr Ron Brown explains the Absolute Risk Reduction for the Pfizer vaccine (0.7%), how to calculate it from the data that Pfizer have provided and why the figure is important for the public to understand.


He says the ARR is a more important figure for the public than the Relative Risk Reduction (RRR) (95%).

An ARR of 0.7% means that you are 0.7% less likely to catch Covid-19 if you take the Pfizer vaccine than you would be if you did not take the Pfizer vaccine. This is from Pfizer's own data. This figure takes into consideration the real life probability of catching covid from the population in the first place. In NZ, this figure would be even lower.

The Relative Risk Reduction measures the reduction in risk compared to placebo (control) risk. That is, many less people caught Covid compared to the normal population group (control).

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Abstracts of the referenced papers: