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Oct
27
Dissertation Defense: Rayleen Lewis
10:00 AM - 12:00 PM
Wright Hall, Room 102C
Date: 10/27/2025
Time: 10:00a-12:00n
Building: Wright Hall 102C
Title: Assessment of Human Papillomavirus (HPV) Antibodies: Impact of the National U.S. Vaccination Program and Sex-Differences After Vaccination
Abstract:
Human papillomavirus (HPV) causes anogenital warts and six types of cancer. Fortunately, vaccines were developed for HPV prevention. In 2006, the United States began a national HPV vaccination program routinely recommending vaccination with the quadrivalent HPV vaccine (4vHPV) for females ages 11–12 years, with catch-up through age 26 years. The program was expanded to include males in 2011. In 2015, a nine-valent HPV vaccine (9vHPV) was licensed and recommended. Clinical trials have demonstrated that HPV vaccines elicit strong immune responses and are highly efficacious against vaccine-type HPV infection and related diseases. However, gaps in knowledge remain regarding antibody responses following vaccination. This doctoral research addressed two such gaps. First, the study assessed the impact of the national HPV vaccination program on HPV antibody levels among U.S. females. Using data from the National Health and Nutrition Examination Survey (NHANES), large increases in 4vHPV-type geometric mean concentrations (GMCs) were observed between the pre-vaccine (2005–2006) and vaccine eras (2013–2016), driven by high GMCs among vaccinated individuals. These increases paralleled national trends in vaccination coverage during the first decade of the U.S. vaccination program. Second, sex differences in vaccine-induced antibody concentrations were evaluated to inform gender-neutral vaccination policies. NHANES data showed that males aged 14–24 years likely vaccinated with 4vHPV had lower 4vHPV-type antibody concentrations than females, while non-4vHPV type concentrations were comparable. Similarly, among adolescents vaccinated with 9vHPV at ages 9–12, males exhibited lower antibody concentrations than females 12–48 months post-vaccination. Although these sex differences were statistically significant, their clinical implications are likely minimal, as even low antibody levels are considered protective. This research provides valuable insights for HPV vaccination policy by enhancing understanding of population-level antibody responses and informing future immunization strategies in the United States.
Human papillomavirus (HPV) causes anogenital warts and six types of cancer. Fortunately, vaccines were developed for HPV prevention. In 2006, the United States began a national HPV vaccination program routinely recommending vaccination with the quadrivalent HPV vaccine (4vHPV) for females ages 11–12 years, with catch-up through age 26 years. The program was expanded to include males in 2011. In 2015, a nine-valent HPV vaccine (9vHPV) was licensed and recommended. Clinical trials have demonstrated that HPV vaccines elicit strong immune responses and are highly efficacious against vaccine-type HPV infection and related diseases. However, gaps in knowledge remain regarding antibody responses following vaccination. This doctoral research addressed two such gaps. First, the study assessed the impact of the national HPV vaccination program on HPV antibody levels among U.S. females. Using data from the National Health and Nutrition Examination Survey (NHANES), large increases in 4vHPV-type geometric mean concentrations (GMCs) were observed between the pre-vaccine (2005–2006) and vaccine eras (2013–2016), driven by high GMCs among vaccinated individuals. These increases paralleled national trends in vaccination coverage during the first decade of the U.S. vaccination program. Second, sex differences in vaccine-induced antibody concentrations were evaluated to inform gender-neutral vaccination policies. NHANES data showed that males aged 14–24 years likely vaccinated with 4vHPV had lower 4vHPV-type antibody concentrations than females, while non-4vHPV type concentrations were comparable. Similarly, among adolescents vaccinated with 9vHPV at ages 9–12, males exhibited lower antibody concentrations than females 12–48 months post-vaccination. Although these sex differences were statistically significant, their clinical implications are likely minimal, as even low antibody levels are considered protective. This research provides valuable insights for HPV vaccination policy by enhancing understanding of population-level antibody responses and informing future immunization strategies in the United States.
