Response to ‘Declines in anogenital warts diagnoses since the change in 2012 to use the quadrivalent HPV vaccine in England: data to end 2017’ by Checchi et al

In England, although not anticipated, a reduction in genital warts (GW) diagnoses was observed from the first years of the human papillomavirus (HPV) vaccination programme using the adjuvanted bivalent vaccine, suggesting potentially cross-protective effect of the vaccine against GW.1 In their recent publication, Checchi et al 2 present results of the GW surveillance programme in England since introduction of the HPV vaccination in 2008, attributing most of the impact observed today to the switch from the bivalent to the quadrivalent …