A Longitudinal Cohort Study to Assess Effectiveness and B-memory Response to the Quadrivalent HPV Vaccine 9 Years Post-vaccination Among HIV-Infected Boys and Girls Ages 9-14 Years in Kenya
A Longitudinal Cohort Study to Assess Effectiveness and B-memory Response to the Quadrivalent HPV Vaccine 9 Years Post-vaccination Among HIV-Infected Boys and Girls Ages 9-14 Years in Kenya
The risk for Human Papillomavirus (HPV) infection persists through an individual sexual life and duration of protection is critical to vaccine effectiveness in protection from oncogenic hrHPV infection. HIV-infected individuals have an increased risk for HPV infection, and persistent infection.
Most vaccine efficacy data among HIV-infected adolescents is represented by immunogenicity data, and there is little published literature on vaccine effectiveness as assessed by persistent incident genital HPV infection.
Investigators shall re-enroll a cohort of previously vaccinated HIV-infected girls and boys for assessment of genital HPV infection 9-years post initial 3 doses of vaccination with quadrivalent HPV vaccine at ages 9 to 14 years.
Background: Genital Human Papilloma Virus (HPV) infections occur rapidly after sexual debut, and immunosuppressed individuals are at greater risk for incident and persistent infection. HPV vaccine contains virus-like particles (VLP), which are highly immunogenic and induce a robust humoral response that has been demonstrated to confer long term protection from HPV infection and associated disease among HIV-uninfected individuals. The magnitude of type-specific vaccine induced neutralizing HPV antibody responses are diminished among HIV-infected compared to uninfected individuals.
There is no established minimum level of antibody that predicts protection against HPV infection or associated disease, the impact of lower antibody titers among HIV infected individuals on vaccine efficacy is unknown. The risk of HPV exposure persists throughout a person's sexual life and the duration of protection, especially when the vaccine is given in the early adolescent period is critical to vaccine effectiveness. Long lasting memory is characterized by memory B cells and long-lived plasma cells and a QHPV booster dose has demonstrated an anamnestic response among HIV-infected adolescents.
HPV efficacy and effectiveness data for HIV-uninfected individuals has informed the current World Health Organization (WHO) two-dose vaccine schedule. The field lacks data on effectiveness of three dose or two-dose for the HIV-infected adolescents. The current on-going research for single dose schedules gives urgency to the determination of long-term efficacy of three HPV vaccine 231 doses for the HIV-infected adolescent.
Investigators shall recall HIV-infected girls and boys who were previously vaccinated at ages 9-14 years with three doses of the quadrivalent vaccine (QHPV) in 2014 and evaluated for vaccine immunogenicity.
Method: The participants will be assessed for genital warts and genital HPV infection. Type specific HPV DNA will be assessed using genital swabs and genital warts assessed through physical examination among sexually active participants at enrollment, month 6 &12.
Among those that have not become sexually active, or that decline a genital exam, a self-collected swab will be requested. A sub-set of approximately 30 participants, will receive a booster dose of QHPV, from this subset, Peripheral Blood Mononuclear Cells (PBMC) and plasma samples will be collected at enrollment, at month 1 and month 12 to evaluate for memory B and T cell responses.
The total duration of study follow up will be 12 months.
Inclusion Criteria:
Exclusion Criteria:
Thika, Kiambu County, Kenya