這是原作者的評論

“VE estimation relies on vaccinated and unvaccinated individuals behaving in a similar fashion in their every-day lives with respect to COVID-19 precautions and exposure to infection risk. It is conceivable that the increasingly small cohort of unvaccinated individuals that remains in Denmark takes further precautions (precisely because they are not well protected), engage less in social activities, etc. Such discrepancies in risk behaviour between vaccinated and unvaccinated individuals will lead to an underestimated VE.”