Clinical attack rates in the northern hemisphere. Estimated clinical attack rate of 26 selected countries in the northern hemisphere for the reference stochastic forecast output (SFO) set coupled with mass vaccination campaigns, and the pre-exposure immunity SFO set with vaccinations, both assuming a proportion of asymptomatic infections, p
, of 45%. The box plots indicate the 95% and 50% reference ranges, with the median value of the simulated attack rates obtained by the analysis of 2,000 stochastic realizations of the model for α
min being 0.65.