A prospective cohort study of immunogenicity of quadrivalent human papillomavirus vaccination among Alaska Native Children, Alaska, United States

• Published in: Vaccine 2020-09, Vol.38 (42), p.6585-6591
• Main Authors: Bruce, Michael G., Meites, Elissa, Bulkow, Lisa, Panicker, Gitika, Hurlburt, Debby, Lecy, Danielle, Thompson, Gail, Rudolph, Karen, Unger, Elizabeth R., Hennessy, Thomas, Markowitz, Lauri E.
• Format: Article
• Language: English
• Subjects: Adolescent; Age; Alaska; Alaska Native; Alaska Natives; Antibodies; Antibodies, Viral; Antibody response; Child; Children; Children & youth; Cohort analysis; Cohort Studies; Cohort study; Enrollments; Enzyme-linked immunosorbent assay; Female; Girls; Human papillomavirus; Human papillomavirus (HPV); Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18; Humans; Immunization; Immunogenicity; Immunoglobulin G; Male; Males; Medical laboratories; Papillomavirus Infections - prevention & control; Papillomavirus Vaccines; Prospective Studies; Quadrivalent HPV vaccine (4vHPV); Questionnaires; United States; Vaccination; Vaccines; Viruses
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2020.08.005

In the United States, HPV vaccination is routinely recommended at age 11 or 12 years; the series can be started at age 9. We conducted a cohort study to assess long-term immunogenicity of quadrivalent HPV vaccine (4vHPV) in an American Indian/Alaska Native (AI/AN) Indigenous population. During 2011–2014, we enrolled AI/AN girls and boys aged 9–14 years, who were vaccinated with a 3-dose series of 4vHPV. Serum specimens were collected at five time points: immediately prior to doses 2 and 3, and at one month, one year, and two years after series completion. Antibody testing was performed using a multiplex virus-like-particle-IgG ELISA for 4vHPV types (HPV 6/11/16/18). Among 477 children (405 girls/72 boys) completing the 3-dose series, median age at enrollment was 11.2 years. Of the 477, 72 (15%) were tested before dose 2 and 70 (15%) before dose 3. Following series completion, 435 (91%) were tested at one month, 382 (80%) at one year, and 351 (74%) at two years. All tested participants had detectable antibody to 4vHPV types at all time points measured. Geometric mean concentrations (GMCs) for 4vHPV types at one month and two years post-series completion were 269.9 and 32.7 AU/ml for HPV6, 349.3 and 42.9 AU/ml for HPV11, 1240.2 and 168.3 IU/ml HPV16, and 493.2 and 52.2 IU/ml for HPV18. Among children tested after each dose, GMCs after doses 1 and 2 were 3.9 and 32.2 AU/ml for HPV6, 5.3 and 45.6 AU/ml for HPV11, 20.8 and 187.9 IU/ml for HPV16; and 6.6 and 49.7 IU/ml for HPV18. No serious adverse events were reported. All AI/AN children developed antibodies to all 4vHPV types after vaccination. GMCs rose after each dose, then decreased to a plateau over the subsequent two years. This cohort will continue to be followed to determine duration of antibody response.