Detailed analysis of the Cochrane HPV vaccines review we submitted on June 4th , 2018, as a comment via the Cochrane website. Our comment highlights relevant methodological flaws in the review: (a) studies’ quality not properly assessed; (b) post-hoc subgroup analyses presented as RCT results; (c) reporting bias not acknowledged; (d) selective reporting not taken into consideration; (e) biased trial designs; (f) unpublished data not included; (g) COIs in the authors’ group; (h) n=7 studies on Gardasil® included, n=18 for Cervarix® – the latter not being marketed in the U.S. anymore. Published on August 9th 2018, two months after submission, as: Riva C, Tinari S, Spinosa JP. Cochrane review on HPV vaccines: Concerns over methodological flaws in the assessment of vaccines’ efficacy. Comment on Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors. Cochrane Database of Systematic Reviews. Available from https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009069.pub3/detailed-comment/en?messageId=154255807 The first version (June 4th, 2018) was amended on September 21st, 2018 to include a minor correction we requested. In our first submission, indeed, we stated wrongfully that Lehtinen’s study on Cervarix® mentioned the limitation of the post-hoc subgroup analysis performed as TVC-naïve analysis, whereas Munoz had not mentioned the same issue about Gardasil® data. We corrected this statement and the updated text states as follows: “The limitation of this type of analysis is not mentioned in Lehtinen’s study regarding Cervarix and in Munoz’s study regarding Gardasil”. In September 2018 we also reiterated our request to let us publish in this page our conflicts of interest declarations. As in June we submitted our comment to the published HPV vaccines Cochrane review we noticed the publication form didn’t prompt the insertion of authors COIs. To our explicit request of letting us declare our COIs, Cochrane replied: “we do currently only ask for direct financial conflicts of interest, but (…) are reviewing a policy for seeking non-financial conflicts”.