Re: Effect of the human papillomavirus (HPV) quadrivalent vaccine in a subgroup of women with cervical and vulvar disease: retrospective pooled analysis of trial data
The authors describe their significant finding as "The incidence of any subsequent HPV related disease was 6.6 and 12.2 in vaccine and placebo recipients respectively (46.2% reduction (95% confidence interval 22.5% to 63.2%) with vaccination)" This is further detailed in table 2.
Furthermore the authors describe an unexpected finding in table 3: "Impact of quadrivalent HPV vaccine on incidence of subsequent cervical intraepithelial neoplasia grade I or worse* associated with 10 tested non-vaccine HPV types among women who had undergone cervical surgery". The effect is similar, a 42.5% reduction.
In summary, the authors found a similar reduction in subsequent diseases of all HPV types (46.2%) and non-vaccine HPV types (42.5%). This leads to the conclusion that the reduction in subsequent disease was unrelated to the vaccination. The only other possibility would imply that the vaccine was active even on virus types not contained in the vaccine.
Competing interests: No competing interests