The spermicide nonoxynol-9 does not inactivate papillomavirus

Vaginal spermicides are effective contraceptive, and are also capable of inactivating many sexually transmitted pathogens by their detergent effect on bacterial cell membranes and viral envelopes. A 5% concentration of nonoxynol-9, the most frequently used active ingredient of spermicides, was tested for its ability to reduce the transforming activity of bovine papillomavirus type 1 (BPV-1), and the infectivity of BK virus (BKV) and cytomegalovirus (CMV). Nonoxynol-9 markedly reduced the infectivity of CMV, an enveloped virus, but did not significantly affect the activity of the nonenveloped viruses BPV-1 and BKV. Papillomavirus infections are strongly implicated in the etiology of cervical cancer. The reported protective effect of vaginal spermicides against cervical cancer is very likely not mediated by direct inactivation of papillomaviruses by the spermicide.