HPV Vaccine for Low Lymphocyte Count

Overseen By Andrea Lisco, M.D.

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)

Must not be taking: Glucocorticosteroids, Immunomodulants

Disqualifiers: HIV, Cancer, Autoimmune, Pregnancy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 7

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether the HPV vaccine, GARDASIL 9, can benefit individuals with idiopathic CD4 T cell lymphocytopenia (ICL). People with ICL often experience severe HPV-related conditions, such as warts, lesions, and cancers. The trial aims to determine if the vaccine can reduce these issues. Individuals aged 18-65 with ICL and healthy participants may qualify. Participants will receive three doses of the vaccine and undergo various health checks throughout the study. As a Phase 2 trial, this research focuses on assessing the treatment's effectiveness in an initial, smaller group.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are using systemic glucocorticosteroids or certain immunomodulants, you may not be eligible to participate.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research has shown that Gardasil 9, the HPV vaccine under study, is generally well-tolerated. Studies have found its safety profile similar to Gardasil, an earlier version of the vaccine, indicating that Gardasil 9's side effects are mostly mild. Common side effects include soreness at the injection site, mild fever, and headaches, while serious side effects are rare.

In another study, participants received either two or three doses of Gardasil 9, and the safety results were consistent regardless of the number of doses. This consistency demonstrates the vaccine's safety for both dosing schedules.

The FDA has already approved Gardasil 9 to prevent HPV-related diseases in the general population, confirming its safety. For individuals with ICL, the current trial aims to determine if Gardasil 9 is equally safe and effective in protecting against HPV-related diseases. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Researchers are excited about Gardasil 9 for low lymphocyte count because it offers a unique approach by utilizing a vaccine typically known for preventing HPV infections. Unlike conventional treatments for low lymphocyte count, which often involve medications to stimulate white blood cell production or manage symptoms, Gardasil 9 is being explored for its potential to enhance immune function through vaccination. This innovative use of a vaccine could potentially offer a new mechanism of action, tapping into the body's ability to respond to pathogens and potentially improving immune resilience. By repurposing an existing vaccine, researchers hope to find a novel and effective way to support the immune system in individuals with low lymphocyte counts.

What evidence suggests that the HPV vaccine might be an effective treatment for low lymphocyte count?

Research has shown that the HPV vaccine, Gardasil 9, effectively reduces HPV infections. In young females, HPV infections decreased by 56% within four years of the vaccine's introduction. The vaccine helps the body remember how to fight HPV over time, providing long-term protection. It has been particularly effective in younger age groups, with success rates between 74% and 93%. This trial will test Gardasil 9 in individuals with low lymphocyte counts (ICL) and healthy volunteers to evaluate its benefits in this specific group, as the long-term effectiveness in people with ICL remains unclear. ^{6 7 8 9 10}

Who Is on the Research Team?

Andrea Lisco, M.D.

Principal Investigator

National Institute of Allergy and Infectious Diseases (NIAID)

Are You a Good Fit for This Trial?

Adults aged 18-70 with idiopathic CD4 T cell lymphocytopenia (ICL) or healthy volunteers meeting specific CD4 count criteria. Participants must not be pregnant, breastfeeding, have had GARDASIL 9 before, severe allergies to vaccine components, HIV, certain acute illnesses or immunodeficiencies, recent cancer treatments or immunomodulants.

Inclusion Criteria

I agree to use birth control if there's a chance I could get pregnant.

I started hormonal treatment at least a month before the first dose of the study drug.

Healthy volunteers must have CD4 cell count of greater than or equal to 450 cells/microL within 90 days prior to day 0.

Exclusion Criteria

I have HIV or another type of immune system problem.

I haven't had chemotherapy or immune system treatments in the last 6 months.

Receipt of ACIP recommended immunizations within 1 week of day 0.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Baseline

Participants undergo baseline assessments including physical exam, medical history, and apheresis

1 day

1 visit (in-person)

Vaccination

Participants receive 3 doses of the GARDASIL 9 vaccine over 6 months

6 months

3 visits (in-person)

Follow-up

Participants are monitored for safety and immunogenicity, with follow-up visits 1 and 18 months after the last vaccine dose

18 months

2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Gardasil 9

Trial Overview The trial is testing the effectiveness of the HPV vaccine GARDASIL 9 in people with ICL compared to healthy individuals. It involves three doses over six months and follow-up visits for up to 18 months after the last dose to monitor immune response and side effects.

How Is the Trial Designed?

Group I: ICL and Healthy Volunteers Experimental Treatment 1 Intervention

Biological/Vaccine

Who Is Running the Clinical Trial?

National Institute of Allergy and Infectious Diseases (NIAID)

Lead Sponsor

Trials

3,361

Recruited

5,516,000+

Published Research Related to This Trial

The nine-valent HPV vaccine, Gardasil9, significantly increases the efficacy against cervical cancer from 70% to 90% compared to the quadrivalent vaccine, covering a broader range of HPV types.

Gardasil9 also provides high efficacy (97%) against lesions associated with HPV types 31, 33, 45, 52, and 58, while maintaining similar effectiveness against HPV types 6, 11, 16, and 18 as the quadrivalent vaccine.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Nine-valent HPV vaccine - new generation of HPV vaccine]. Fait, T., Dvořák, V., Pilka, R.[2018]

The two-dose HPV vaccine series for pre-adolescent girls (ages 9-15) is effective in providing protection against HPV 16 and other types, with the World Health Organization recommending this schedule since 2015, while older women still require a three-dose series.

Gardasil9 and Cervarix both show strong efficacy in preventing HPV infections, with Cervarix offering a potentially more cost-effective option due to its sustained high antibody levels and the possibility of effective protection with just one dose.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

HPV vaccines - A review of the first decade. Harper, DM., DeMars, LR.[2022]

The post-licensure safety profile of HPV vaccines Gardasil and Cervarix was evaluated using data from three sources, including VigiBase and VAERS, confirming that the reported adverse events align with existing safety data.

The analysis showed that the safety profiles of both vaccines are consistent with the information provided in their Summary of Product Characteristics (SPC), indicating that they are safe for public use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Postlicensure safety evaluation of human papilloma virus vaccines. Labadie, J.[2015]

The 9-valent HPV vaccine (Gardasil 9®) significantly increases protection against cervical cancer by covering 9 oncogenic HPV types, raising potential protection from about 70% to 90%, based on clinical trials involving young women.

Clinical trials demonstrated that the 9vHPV vaccine has a comparable safety profile and immunogenicity to the original 4-valent vaccine, with a 2-dose regimen showing similar effectiveness in younger boys and girls compared to the standard 3-dose regimen for older women.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Expanded strain coverage for a highly successful public health tool: Prophylactic 9-valent human papillomavirus vaccine. Zhang, Z., Zhang, J., Xia, N., et al.[2019]

In a study of 266,647 doses of Gardasil-9® administered in Puglia, Italy, only 22 adverse events following immunization (AEFIs) were reported, resulting in a low reporting rate of 8.25 per 100,000 doses, indicating a favorable safety profile for the vaccine.

Out of the 22 reported AEFIs, only 5 were classified as serious, with 2 leading to hospitalization; however, only 2 serious AEFIs were consistently associated with the vaccine, suggesting that the benefits of Gardasil-9® outweigh the risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Real-Life Safety Profile of the 9-Valent HPV Vaccine Based on Data from the Puglia Region of Southern Italy. Di Lorenzo, A., Berardi, P., Martinelli, A., et al.[2022]

Both Gardasil and Cervarix HPV vaccines have shown outstanding efficacy in preventing infections and related conditions in young women, with excellent safety profiles and only mild to moderate side effects reported.

Neither vaccine is effective in treating existing HPV infections or lesions, but they provide strong protection against specific HPV types for at least four years, with Gardasil also preventing genital warts.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An update of prophylactic human papillomavirus L1 virus-like particle vaccine clinical trial results. Schiller, JT., Castellsagué, X., Villa, LL., et al.[2022]

In a study involving 12,066 women aged 9 to 26 years who received the HPV vaccines Gardasil® and Cervarix® over three years, 61% reported experiencing mild and transient adverse events after the first dose.

The high rate of reported adverse events is attributed to the study's design, which encouraged participants to document all occurrences, highlighting the importance of ongoing surveillance for vaccine safety, especially for newly marketed vaccines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Human papillomavirus vaccine register]. Spila-Alegiani, S., Da Cas, R., Giambi, C., et al.[2013]

In a study of 316 females who reported suspected severe adverse reactions to the HPV vaccine, it was found that these individuals had significantly higher health care-seeking behavior in the two years prior to vaccination compared to a control group of over 163,000 individuals.

The cases showed increased consultations for various health issues, including psychological support and musculoskeletal problems, suggesting that pre-existing health conditions may influence perceptions of vaccine safety and should be considered when evaluating vaccine safety signals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pre-Vaccination Care-Seeking in Females Reporting Severe Adverse Reactions to HPV Vaccine. A Registry Based Case-Control Study. Mølbak, K., Hansen, ND., Valentiner-Branth, P.[2019]

All three HPV vaccines (bivalent, quadrivalent, and 9vHPV) show high efficacy in preventing infections from specific HPV types and associated high-grade cervical dysplasia in women who have not been previously exposed to HPV.

While the bivalent and quadrivalent vaccines have demonstrated early clinical effectiveness in reducing HPV 16 and 18 prevalence, the overall benefits of HPV vaccination in reducing cervical cancer are still largely theoretical, highlighting the need for large-scale studies to confirm long-term effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of 2-, 4- and 9-valent HPV vaccines on morbidity and mortality from cervical cancer. Luckett, R., Feldman, S.[2018]

In a study of 178 women under 45 years old with a history of HPV disease, those who received the quadrivalent HPV vaccine after treatment had a significantly lower recurrence rate of HPV-linked disease (3.4%) compared to those who did not receive the vaccine (13.5%).

The results indicate that HPV vaccination during follow-up can effectively reduce the risk of disease recurrence, suggesting that it should be considered as part of post-treatment management for women with HPV-related conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Indication of prophylactic vaccines as a tool for secondary prevention in HPV-linked disease. Pieralli, A., Bianchi, C., Auzzi, N., et al.[2019]

The quadrivalent HPV vaccine (Gardasil) effectively stimulated HPV-specific immune responses in HIV-infected young adults undergoing antiretroviral therapy, showing significant increases in various T lymphocyte populations after three doses.

The immune response in HIV-infected individuals was comparable to that of healthy controls, suggesting that the vaccine is both safe and effective in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Human papilloma virus vaccination induces strong human papilloma virus specific cell-mediated immune responses in HIV-infected adolescents and young adults. Rainone, V., Giacomet, V., Penagini, F., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3393366/

Human Papillomavirus Immunization Is Associated with ... Our data indicate that HPV immunization is associated with significant changes in the expression and function of different innate immune receptors, including ...

2. cdc.gov cdc.gov/hpv/hcp/vaccination-considerations/safety-and-effectiveness-data.html

HPV Vaccine Safety and Effectiveness Data As early as 4 years after Gardasil licensure, vaccine-type HPV infections had decreased 56% among 14–19-year-old females.1. Within 12 years ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7175219/

HPV-Specific Systemic Antibody Responses and Memory ... Hence, Gardasil was more effective than Cervarix in the 16–20 y groups, while both vaccines ensure long-term memory B cells in more than 75% of vaccinated ...

4. ijdvl.com ijdvl.com/vaccines-for-human-papillomavirus-infection-a-critical-analysis/

Vaccines for human papillomavirus infection: A critical ... The exact duration of efficacy of the vaccine is not yet known, but studies show good efficacy for at least 5 years. It has not yet been determined whether ...

5. frontiersin.org frontiersin.org/journals/public-health/articles/10.3389/fpubh.2025.1544220/full

Optimizing HPV vaccine effectiveness: impact of ... The findings suggest that the highest vaccine effectiveness is observed in younger age groups (ages 9–14: 74–93%) and decreases with age.

6. cdc.gov cdc.gov/vaccine-safety/vaccines/hpv.html

Human Papillomavirus (HPV) Vaccine Safety The safety findings from these pre-licensure studies show that Gardasil 9 has a similar safety profile to Gardasil, an earlier version of the vaccine. The main ...

7. academic.oup.com academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaf241/8129247

Immunogenicity and Safety of 2 Versus 3 Doses of 9-Valent ... This was a prospective study comparing 2 doses (months 0 and 6) versus 3 (months 0, 2, and 6) doses of 9-valent vaccine (Gardasil 9, Merck Sharp ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2988719/

HPV vaccine: an overview of immune response, clinical ... Comparison of the immunogenicity and safety of CervarixTM and Gardasil® human papillomavirus (HPV) cervical cancer vaccines in healthy women aged 18-45 years.

9. immunize.org immunize.org/ask-experts/topic/hpv/

Ask the Experts: HPV (Human Papillomavirus) Read answers by medical experts to healthcare provider questions on vaccines and HPV (Human Papillomavirus).

10. tandfonline.com tandfonline.com/doi/full/10.1080/21645515.2025.2530831

Adverse events following 9-valent human papillomavirus ... To further clarify potential safety signals attributable solely to GARDASIL 9, a subanalysis was conducted using serious adverse events (SAEs) reported in cases ...