Vaccine efficacy 'cheap trick' by exclusion

Simply ignoring - rather than misclassifying recently vaccinated cases - also creates the illusion of efficacy.

Our main simulated example of the vaccine efficacy ‘cheap trick’ was based on the assumption that those who tested positive for infection within a short period after vaccination (e.g., 7, 14 or 21 days) were classified as unvaccinated. In a typical mass (placebo) vaccine roll-out this cheap trick guarantee the illusion of efficacy starting at over 90% b…