The vaccinated proportion of people with COVID-19 needs context.

We read the Correspondence by Günter Kampf with surprise, as it appears to argue that the base-rate fallacy is, in fact, not a fallacy. In the context of COVID-19 vaccines, the base-rate fallacy is often described as the illusion that vaccines are ineffective because, in highly vaccinated populations, the majority of COVID-19 cases occur among vaccinated people. For example, if a population is 99% vaccinated against a hypothetical virus and 51% of infected individuals have been vaccinated, the base-rate fallacy (falsely) implies that the vaccine is ineffective at preventing infection. Of course, if the vaccine was truly ineffective, we would expect about 99% of infected individuals to have been vaccinated.

Kampf reports the proportions of people who were vaccinated in three groups of COVID-19 cases, but in each instance fails to report the vaccinated proportion of the total population; without such context, the proportion of people with COVID-19 who were vaccinated has little meaning. Although Kampf modified the implication of the base-rate fallacy—from vaccines are ineffective, to it is not justified to disapprove of individuals who choose not to be vaccinated—Kampf's piece still captures the essence of the base-rate fallacy. Would Kampf similarly argue that because most road deaths do not involve drunk drivers, acknowledging the harms of drink driving on public health is not justified?