2024-04-25 ::: Comment on “Impact of immune evasion, waning and boosting on dynamics of population mixing between a vaccinated majority and unvaccinated minority” by Fisman et al. (2024): Incorrect definition and application of a parameter ψ

By Denis G Rancourt and Joseph Hickey

Abstract:

We prove that Fisman et al. (2022, 2024) incorrectly define and apply a parameter ψ. They rely solely on their parameter ψ to erroneously advance that the risk of infection incurred by vaccinated persons due to contacts with unvaccinated persons is alarmingly “disproportionate”. Their faulty application of ψ would imply that the said risk increases with increasing segregation from the unvaccinated (up to complete segregation, η = 1), increases with increasing vaccination coverage (up to complete coverage, Pv = 1) and increases with increasing vaccine efficacy (up to perfect vaccine efficacy, VE = 1), which is contrary to reason. We show that Fisman et al.’s published errors in applying ψ have a potential to cause harm by encouraging overly aggressive (disproportionate) public health policies and interventions.