Depletion-of-susceptibles Bias in Analyses of Intra-season Waning of Influenza Vaccine Effectiveness

Clin Infect Dis. 2020 Mar 17;70(7):1484-1486. doi: 10.1093/cid/ciz706.


Bias arises in studies of waning vaccine effectiveness when higher-risk individuals are depleted from the at-risk population at different rates between study groups. We examined how this bias arises and how to avoid it. A reanalysis of data from California confirmed a finding of intra-season waning of influenza vaccine effectiveness.

Keywords: bias; depletion of susceptibles; influenza; vaccine effectiveness; waning.