CONTROLLED-RELEASE OF ANTIBODIES FOR LONG-TERM TOPICAL PASSIVE IMMUNOPROTECTION OF FEMALE MICE AGAINST GENITAL HERPES

Current methods for sexually transmitted diseases (STD) prophylaxis, w hich can be disruptive and inconvenient, must be used before each act of sexual intercourse, so a method that provides protection over the c ourse of many acts is desirable. We used a mouse model of vaginally-tr ansmitted herpes simplex virus 2 (HSV-2) infection to test polymeric c ontrolled-release devices for sustained passive immunoprotection. Vagi nal disks were prepared by dispersing a monoclonal antibody to HSV-2 ( III-174) within a matrix of poly(ethylene-co-vinyl acetate); these dis ks released 2 to 40 mu g/day of antibody into buffered water. When dis ks were placed in the vagina, large amounts of III-174 (5 to 3,000 ng) were recovered from the vaginal fluid over the next 8 days. Mice were vaginally challenged with 10 ID50 of HSV-2 either 3 or 7 days after d isk placement; no mice receiving III-174 disks became infected, while 65% of control mice receiving identical disks with nonspecific IgG did . Controlled-release disks with III-174 provided significant protectio n against HSV-2 infection (p < 0.005). This new technology for long-te rm STD prophylaxis should increase user compliance, a factor limiting the efficacy of current methods.