Sperm washing - yes or no? An open issue still to be debated.

We are pleased that our recent publication (Fenizia et al., 2020) has opened a constructive discussion (Garolla et al., 2020). We agree with Garolla and colleagues that there are detrimental effects of human papilloma virus (HPV) on fertility and pregnancy outcomes, which is why we feel it is important to investigate some potential countermeasures. As stated in our paper, further studies should be performed. However, we would like to reply to the authors’ specific concerns as follows: (i) PCR is the preferred designated method for virus detection, including clinical diagnosis of HPV (Depuydt et al., 2019), HIV (Fearon, 2005) and SARS-CoV-2 in the current COVID-19 pandemic (Sethuraman et al., 2020). Highly specific and highly sensitive, PCR allows HPV-detection of only a few copies in the whole ejaculate, including cell-free HPV in seminal plasma. Moreover, we believe that consideration of the findings of Song et al. (2017) scarcely apply to HPV detection, given that the aim there was to investigate intra-clonal heterogeneity in cancer, making bulk analyses inappropriate in that case; (ii) notoriously, HPV is still detected upon 'standard' sperm-washing procedures (Foresta et al., 2011), as confirmed in Figure 1 in Garolla et al. (2020). However, we apply the 'combined' sperm-washing procedure, which differs from the 'standard' one (Fenizia et al., 2020; Savasi et al., 2007); (iii) thus far, there is no universal HPV-screening in assisted reproductive technology procedures and we aim to raise awareness of the potential importance of this step. We also recommend caution and we encourage other suitable beneficial approaches to be adopted, including an anti-HPV vaccine (Garolla et al., 2018). Indeed, we believe that a joint, double-blinded study could be helpful in defining more appropriate guidelines, as proposed at the 2019 meeting of the Italian Society for the Study of Fertility and Sterility and Reproductive Medicine (SIFES–MR).