Durability of Protection Afforded by Fewer Doses of the HPV16/18 Vaccine: The CVT Trial
Year: 2017
Type: article
Abstract: Background: Previously, we demonstrated similar human papillomavirus (HPV)16/18 vaccine efficacy estimates and stable HPV16/18 antibody levels four years postvaccination in a nonrandomized analysis of women who received a varying number of doses of the bivalent HPV16/18 vaccine. Here we extend data to seven years following initial vaccination. Methods: We evaluated HPV16/18-vaccinated women who received one (n = 134), two (n 0/1 = 193, n 0/6 = 79), or three doses (n = 2043) to a median of 6.9 years postvaccination. Cervical HPV DNA was measured with the SPF10- DEIA-LiPA PCR system; HPV16/18-specific antibody levels were measured using enzyme-linked immunosorbent assays (n = 486). Infection and immunological measures were compared across vaccine dose groups. Prevalent HPV infection at year 7 was also compared with an unvaccinated control group (UCG). All statistical tests were two-sided. Results: Among women in the three-dose, two-dose 0/6 , two-dose 0/1 , and one-dose groups, cumulative incident HPV16/18 infection rates (No. of events/No. of individuals) were 4.3% (88/2036, 95% confidence interval [CI] = 3.5% to 5.3%), 3.8% (3/78, 95% CI = 1.0% to 10.1%), 3.6% (7/192, 95% CI = 1.6% to 7.1%), and 1.5% (2/133, 95% CI = 0.3% to 4.9%; P = 1.00, .85, .17 comparing the two-dose 0/6 , two-dose 0/1 , and one-dose groups to the three-dose group, respectively). The prevalence of other carcinogenic and noncarcinogenic HPV types, excluding HPV16/18/31/33/45, were high and not statistically different among all dose groups, indicating that the low incidence of HPV16/18 in the one- and two-dose groups was not due to lack of exposure. At seven years, 100% of participants in all dose groups remained HPV16 and HPV18 seropositive. A non-statistically significant decrease in the geometric mean of the HPV16 antibody levels between years 4 and 7 was observed among women in the three-dose group: -10.8% (95% CI = -25.3% to 6.6%); two-dose (0/6 months) group: -17.3% (95% CI = -39.3% to 12.8%), two-dose (0/1 month) group: -6.9% (95% CI = -22.1% to 11.2%), and one-dose group: -5.5% (95% CI = -29.7% to 27.0%); results were similar for HPV18. Conclusions: At an average of seven years of follow-up, we observed similar low rates of HPV16/18 infections and slight, if any, decreases in HPV16/18 antibody levels by dose group.
DOI: 10.1093/jnci/djx158
Authors: Mahboobeh Safaeian, Joshua N. Sampson, Yuanji Pan, Carolina Porras, Troy J. Kemp, Rolando Herrero, Wim Quint, Leen Jan van Doorn, John Schussler, Douglas R. Lowy, John Schiller, Mark T. Schiffman, Ana Cecilia Rodriguez, Mitchell H. Gail, Allan Hildesheim, Paula Gonzalez, Ligia A. Pinto, Aimée R. Kreimer, for the Costa Rica HPV Vaccine Trial (CVT) Group, González Paula, Rolando Herrero, Silvia E. Jiménez, Carolina Porras, Ana Cecilia Rodríguez, Allan Hildesheim, Aimée R. Kreimer, Douglas R. Lowy, Mark Schiffman, John T. Schiller, Mark Sherman, Sholom Wacholder, Ligia A. Pinto, Troy J. Kemp, Mary K. Sidawy, Wim Quint, Leen-Jan van Doorn, Linda Struijk, Joel M. Palefsky, Teresa M. Darragh, Mark H. Stoler
Institutions: National Institutes of Health, National Cancer Institute, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc. (United States), Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud, Centre international de recherche sur le cancer, DDL Diagnostic Laboratory
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2757094995