...despite several studies showing consistent results in the direction of efficacy, there is still skepticism in the scientific community about the use of the HPV vaccine as an adjuvant therapy, after local treatment, against relapses. ...although a post-operative vaccination constitutes an effective preventive strategy for women at high risk of new infection due to their promiscuity or a possible state of immunodeficiency, protection against new infection has not an adjuvant relevance and the interval between surgery and vaccination would not constitute an essential requirement. ...in this scientific controversy, the absence of comprehension of the biological mechanism introduces an uncertainty that cannot be overcome by the statistical precision of pooled estimates coming from individually inconclusive studies. ...trials testing preventive interventions usually are only a proof of principle of efficacy, and the understanding of underlying mechanisms is necessary to anticipate long-term effects that cannot be reasonably directly observed in time horizon of a trial. Lichter K, Krause D, Xu J, Tsai SHL, Hage C, Weston E, Eke A, Levinson K. Adjuvant human papillomavirus vaccine to reduce recurrent cervical dysplasia in Unvaccinated women: a systematic review and Meta-analysis.