The topical microbicide PRO 2000 protects against genital herpes infectionin a mouse model

Vaginal gel formulations containing the naphthalene sulfonate polymer PRO 2 000 are being developed as topical microbicides to protect against infectio n with sexually transmitted disease (STD) pathogens. A mouse model was used to determine whether PRO 2000 could protect against genital herpes in vivo . Animals received a single intravaginal application of 15 mu L of a 10% PR O 2000 aqueous solution or a 4.0% or 0.5% PRO 2000 vaginal gel formulation 20 s prior to intravaginal challenge with 4.0 log(10) pfu of herpes simplex virus type 2, Treatment with the 4.0% gel provided complete protection aga inst infection; treatment with the 0.5% gel or 10% solution provided 81% an d 80% protection, respectively, Furthermore, the 4% gel provided significan t protection even when viral challenge was delayed until 60 min after treat ment. This is the first report to show that PRO 2000 can protect against in fection with an STD pathogen in vivo.