RESUMO
BACKGROUND: Human papillomavirus virus type 16 (HPV-16) and HPV-18 cause a large proportion of oropharyngeal cancers, which are increasing in incidence among males, and vaccine efficacy against oral HPV infections in men has not been previously evaluated. METHODS: Sera and saliva collected in mouthwash and Merocel sponges at day 1 and month 7 were obtained from 150 men aged 27-45 years from Tampa, Florida, and Cuernavaca, Mexico, who received Gardasil at day 1 and months 2 and 6. Specimens were tested for anti-HPV-16 and anti-HPV-18 immunoglobulin G (IgG) levels by an L1 virus-like particle-based enzyme-linked immunosorbent assay. RESULTS: All participants developed detectable serum anti-HPV-16 and anti-HPV-18 antibodies, and most had detectable antibodies in both oral specimen types at month 7 (HPV-16 was detected in 93.2% of mouthwash specimens and 95.7% of sponge specimens; HPV-18 was detected in 72.1% and 65.5%, respectively). Antibody concentrations in saliva were approximately 3 logs lower than in serum. HPV-16- and HPV-18-specific antibody levels, normalized to total IgG levels, in both oral specimen types at month 7 were significantly correlated with serum levels (for HPV-16, ρ was 0.90 for mouthwash specimens and 0.92 for sponge specimens; for HPV-18, ρ was 0.89 and 0.86, respectively). CONCLUSIONS: This is the first study demonstrating that vaccination of males with Gardasil induces HPV antibody levels at the oral cavity that correlate with circulating levels.
Assuntos
Anticorpos Antivirais/imunologia , Papillomavirus Humano 16/imunologia , Papillomavirus Humano 18/imunologia , Boca/imunologia , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Florida , Vacina Quadrivalente Recombinante contra HPV tipos 6, 11, 16, 18/imunologia , Humanos , Imunoglobulina G/imunologia , Masculino , México , Pessoa de Meia-Idade , Saliva/imunologia , Vacinação/métodosRESUMO
The Costa Rica HPV16/18 Vaccine Trial (CVT) showed that four-year vaccine efficacy against 12-month HPV16/18 persistent infection was similarly high among women who received one, two, or the recommended three doses of the bivalent HPV16/18 L1 virus-like particle (VLP) vaccine. Live-attenuated viral vaccines, but not simple-subunit vaccines, usually induce durable lifelong antibody responses after a single dose. It is unclear whether noninfectious VLP vaccines behave more like live-virus or simple-subunit vaccines in this regard. To explore the likelihood that efficacy will persist longer term, we investigated the magnitude and durability of antibodies to this vaccine by measuring HPV16- and HPV18-specific antibodies by VLP-ELISA using serum from enrollment, vaccination, and annual visits through four years in four vaccinated groups; one-dose (n = 78), two-doses separated by one month (n = 140), two doses separated by six months (n = 52), and three scheduled doses (n = 120, randomly selected). We also tested enrollment sera from n = 113 HPV16- or HPV18 L1-seropositive women prevaccination, presumably from natural infection. At four years, 100% of women in all groups remained HPV16/18 seropositive; both HPV16/18 geometric mean titers (GMT) among the extended two-dose group were non-inferior to the three-dose group, and ELISA titers were highly correlated with neutralization titers in all groups. Compared with the natural infection group, HPV16/18 GMTs were, respectively, at least 24 and 14 times higher among the two-dose and 9 and 5 times higher among one-dose vaccinees. Antibody levels following one-dose remained stable from month 6 through month 48. Results raise the possibility that even a single dose of HPV VLPs will induce long-term protection.