Evaluation of Durability of a Single Dose of the Bivalent HPV Vaccine: The CVT Trial.
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ABSTRACT: BACKGROUND:The authors investigated the durability of vaccine efficacy (VE) against human papillomavirus (HPV)16 or 18 infections and antibody response among nonrandomly assigned women who received a single dose of the bivalent HPV vaccine compared with women who received multiple doses and unvaccinated women. METHODS:HPV infections were compared between HPV16 or 18-vaccinated women aged 18 to 25?years who received one (N?=?112), two (N?=?62), or three (N?=?1365) doses, and age- and geography-matched unvaccinated women (N?=?1783) in the long-term follow-up of the Costa Rica HPV Vaccine Trial. Cervical HPV infections were measured at two study visits, approximately 9 and 11 years after initial HPV vaccination, using National Cancer Institute next-generation sequencing TypeSeq1 assay. VE and 95% confidence intervals (CIs) were estimated. HPV16 or 18 antibody levels were measured in all one- and two-dose women, and a subset of three-dose women, using a virus-like particle-based enzyme-linked immunosorbent assay (n?=?448). RESULTS:Median follow-up for the HPV-vaccinated group was 11.3?years (interquartile range = 10.9-11.7?years) and did not vary by dose group. VE against prevalent HPV16 or 18 infection was 80.2% (95% CI = 70.7% to 87.0%) among three-dose, 83.8% (95% CI = 19.5% to 99.2%) among two-dose, and 82.1% (95% CI = 40.2% to 97.0%) among single-dose women. HPV16 or 18 antibody levels did not qualitatively decline between years four and 11 regardless of the number of doses given, although one-dose titers continue to be statistically significantly lower compared with two- and three-dose titers. CONCLUSION:More than a decade after HPV vaccination, single-dose VE against HPV16 or 18 infection remained high and HPV16 or 18 antibodies remained stable. A single dose of bivalent HPV vaccine may induce sufficiently durable protection that obviates the need for more doses.
SUBMITTER: Kreimer AR
PROVIDER: S-EPMC7566548 | biostudies-literature | 2020 Oct
REPOSITORIES: biostudies-literature
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