Randomized controlled trial of an adjuvanted human papillomavirus (HPV) type 6 L2E7 vaccine: infection of external anogenital warts with multiple HPV types and failure of therapeutic vaccination

Background.Cellular immunity is involved in spontaneous clearance of anogenital warts caused, most typically, by human papillomavirus (HPV) type 6 or 11, supporting the concept of therapeutic vaccination. A therapeutic vaccine composed of HPV‐6 L2E7 fusion protein and AS02A adjuvant was evaluated in conjunction with conventional therapies in subjects with anogenital warts. Methods.A total of 457 subjects with anogenital warts were screened, of which 320 with HPV‐6 and/or HPV‐11 infection were enrolled into 2 double‐blind, placebo‐controlled substudies. Three doses of vaccine or placebo were administered along with either ablative therapy or podophyllotoxin. Results.Although a positive trend toward clearance was seen in patients infected with only HPV‐6, in neither substudy did the vaccine significantly increase the efficacy of conventional therapies, despite induction of adequate immune responses. Extensive HPV typing by polymerase chain reaction demonstrated that a majority of screened subjects (73.7%) were infected with HPV‐6 and/or HPV‐11 and that a large proportion (40.1%) were infected with multiple HPV types. HPV types that put subjects at high risk of development of cervical cancer were detected in 39.8% of subjects. Conclusions.Infection with multiple HPV types, including high‐risk types, is common in anogenital wart disease. Therapeutic vaccination failed to increase the efficacy of conventional therapies

Human Monoclonal Anti-Protective Antigen Antibody Completely Protects Rabbits and Is Synergistic with Ciprofloxacin in Protecting Mice and Guinea Pigs against Inhalation Anthrax

Prevention of inhalation anthrax requires early and extended antibiotic therapy, and therefore, alternative treatment strategies are needed. We investigated whether a human monoclonal antibody (AVP-21D9) to protective antigen (PA) would protect mice, guinea pigs, and rabbits against anthrax. Control animals challenged with Bacillus anthracis Ames spores by the intranasal route died within 3 to 7 days. AVP-21D9 alone provided minimal protection against anthrax in the murine model, but its efficacy was notably better in guinea pigs. When Swiss-Webster mice, challenged with five 50% lethal doses (LD(50)s) of anthrax spores, were given a single 16.7-mg/kg of body weight AVP-21D9 antibody dose combined with ciprofloxacin (30 mg/kg/day for 6 days) 24 h after challenge, 100% of the mice were protected for more than 30 days, while ciprofloxacin or AVP-21D9 alone showed minimal protection. Similarly, when AVP-21D9 antibody (10 to 50 mg/kg) was combined with a low, nonprotective dose of ciprofloxacin (3.7 mg/kg/day) and administered to guinea pigs for 6 days, synergistic protection against anthrax was observed. In contrast, a single dose of AVP-21D9 antibody (1, 5, 10, or 20 mg/kg) but not 0.2 mg/kg alone completely protected rabbits against challenge with 100 LD(50)s of B. anthracis Ames spores, and 100% of the rabbits survived rechallenge. Further, administration of AVP-21D9 (10 mg/kg) to rabbits at 0, 6, and 12 h after challenge with anthrax spores resulted in 100% survival; however, delay of antibody treatment by 24 and 48 h reduced survival to 80% and 60%, respectively. Serological analysis of sera from various surviving animals 30 days postprimary infection showed development of a species-specific PA enzyme-linked immunosorbent assay antibody titer that correlated with protection against reinfection. Taken together, the effectiveness of human anti-PA antibody alone or in combination with low ciprofloxacin levels may provide the basis for an improved strategy for prophylaxis or treatment following inhalation anthrax infection