Routine vaccination with HPV vaccine is recommended at age 11 or 12 years. The 3-dose series can be started at age 9. We enrolled American Indian/Alaska Native (AI/AN) children into a study to determine response to human papillomavirus vaccine (4vHPV) post dose 1, 2 and 3, and duration of detectable antibody.
We recruited Alaska Native children aged 9-14 years from 2011-2014 who were vaccinated with 4vHPV. All children were tested one month post dose 3 and a subset was tested post doses 1 and 2. Antibody was measured using a multiplex L1-virus like particle-IgG ELISA.
Among 470 children (400 girls and 70 boys) completing the 3-dose series, 432 (92%) were tested for antibody after dose 3, 71 (15%) post dose 1 and 70 (15%) after dose 2. Overall mean age at dose 1 was 11.2 years. All participants had detectable antibody after dose 3; after dose 1, 96-100% had detectable antibody. Geometric mean concentrations (GMCs) after dose 3 for HPV genotype 6, 11, 16, and 18 were 276.6 AU/ml, 355.6 AU/ml, 1256.4 IU/ml and 504.6 IU/ml, respectively. Among those tested after each dose, GMCs after dose 1, and 2 were: HPV genotype 6 3.8 AU/ml, 32.3 AU/ml; HPV11 5.4 AU/ml, 45.5 AU/ml; HPV16 20.9 IU/ml, 189.6 IU/ml; HPV18 6.1 IU/ml, 49.7 IU/ml. No serious adverse reactions were reported among vaccine recipients.
All Alaska Native children responded to vaccination. GMCs were higher after each vaccine dose. This cohort will be followed for a minimum of 20 years to determine duration of antibody response.