Antitoxin vaccines and pathogen virulence

Abstract
In their mathematical description of vaccine-induced immunity1, Gandon et al. predict that the host's immunity to a microbial toxin will lead to increased virulence of the pathogen without affecting its transmission. However, results obtained using vaccines against two additional bacterial pathogens are not consistent with this prediction. The model proposed by Gandon et al. may therefore be an oversimplification, with the outcome depending on the biological details of both the pathogen and the vaccine.