(Using made up numbers here) Lets say that infection #1 puts the risk of outcome A at 40% Infection #2 puts the risk of outcome A at 60% Infection #3 puts th

(Using made up numbers here) Lets say that infection #1 puts the risk of outcome A at 40% Infection #2 puts the risk of outcome A at 60% Infection #3 puts the risk of outcome A at 70% Each infection increases the risk of outcome A, but it isn't an increasing rate. --- This would be very different from Infection #1 having a risk of outcome A at 10% Infection #2 having a risk of outcome A at 30% Infection #3 having a risk of outcome A at 70% --- The first case that I described matches Figure 5: https://www.nature.com/articles/s41591-022-02051-3/figures/5 https://www.nature.com/articles/s41591-022-02051-3/figures/5 Note the difference in the rate of increase between the infections. Yes, multiple infections increases the risk. However, each subsequent infection has a lower rate of increase of the chance.